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I once met a chap who told me he used his dishwasher without any powder or soap at all, and it still worked.

Now, maybe he was making it up. But i suspect that there is a common class of dish dirt where prolonged steaming and jetting with hot water is adequate in practice - i'd expect anything water-soluble to dissolve in hot water! So, residues from tea or coffee, water-based pasta sauce, fruit juice, jam, etc. It won't work for everything, of course, but it might work for a surprising range of things.

We had a dishwasher with auto-dispense where you pour the whole bottle of detergent into a reservoir and it would automatically dispense what was needed.

Well one day it was getting low I poured a new bottle in and all the dishes weren't getting washed. I called the detergent company to report a defective bottle, but turns out there was some sort of formula change due to a new regulation. Apparently mixing the two together in the auto-dispenser causes them to harden and clog the dispenser. So I tried just pouring it into the manual dispenser, slightly better but the dishes weren't really clean. I called my dishwasher repairman who just told me to buy Finish tabs and we would be fine.

My mother called me weeks later saying that six of her tenants complained that their dishwasher was broken and she had already replaced one (two of the dishwashers were less than two years old). I told her to just gift them all a tub of tabs from Costco which worked.

This happened to me in the car when adding a new kind of windshield wiper fluid over the old one. It did not clog the pipes, but made the resulting fluid very slimy, and it could not be wiped out by the wiper blades. The result was that the windshield became translucent and very hard to see through. When it stayed longer on the windshield, it frosted like ice, making it even harder to see through. I had to stop at a service station and drain all that fluid out, then fill the washer fluid tank with water to clean everything.

The new fluid by itself was fine, it was just the combination of the two that created a reaction.

Didn't happen to be a BMW did it? It was a big issue for a while.

Nope. A quite old VW Polo. Not sure how it could be car specific.

Different brands use different formulations, apparently the brand that the dealership puts in at BMW/MINI doesn't play nicely with some of the brands from supermarkers.

More of an issue for newer cars though, I will give you that.

Because clearly BMW sells it's own special washer fluid for $40 a bottle.

Nah, BMW uses tablets for it's screenwash that are about £7 for six, each makes 5 litres. BMW Part number: 83122298202

Less shipping cost/environmental impact too.

30 litres for around £7 (plus a few pennies for water) doesn't seem bad to me.

I’m in a constant debate with my spouse about the need for prewashing. She’s a prewasher and I am not.

My anecdata based on “feedback” I’ve received over the years:

(1) Greasy and sugary things will go through fine.

(2) Proteins, like supplements, eggs, less cooked meats or cat food, tend to denature more and get stuck/baked to dishes to the point of needing a rewash.

(3) An exception is proteins in a fat emulsion (like mayo) where fat has a stronger influence on the properties of the residue.

This is after trying multiple tablets, even ones that promise pre-wash free dishes, in a pre-Energy Star dishwasher.

I used to get testy when people rinsed the dishes before loading the dishwasher. Then one day I had to take it apart and dig out rice, plastic, beans, and other things that were stopping it up.

This is standard part of dishwasher operation. Every 5-10 loads you refill the jet dry liquid and bang the screen trap out in the trash.

It should be only slightly more difficult than removing lint from the dryer.

With my lack of rinsing this is an every day job in our house. Though we never use rinse aid.

xattt says>"(2) Proteins, like supplements, eggs, less cooked meats or cat food, tend to denature more and get stuck/baked to dishes to the point of needing a rewash."<

Proteins are softened and loosened by soaking in water. Many glues are protein-based and, for that reason, protein-glued items should not be exposed to high humidity or water. For example, most violins are glued with animal hide/hoof or fish protein glues.

Soaking protein in plain water will eventually loosen it completely. The process is reversible: drying re-hardens the protein.

This has been my strategy with some caked on foods but not always an option in the heat of the moment.

An ideal dishwasher would let you load it up over a day or too, and keep the dishes moist but intermittently misting them. Probably terrible for mold and mildew however.

I lived in a co-op in PA during college, we had a "dish sanitizer" instead of a dish washer. It was basically just blasting the shit out of the dishes with crazy hot water. We were supposed to wash them before we put them in there but nobody ever did.

The cafeteria at my dorm had this. High pressure very hot water spray. Took about a minute. All the dishes were ceramic and there was glass and flatware. I don't know if anything plastic or other material could be subjected.

The school cafeteria I worked in had this (was a middle school that also prepared food for some smaller elementaries). We put plastic foodservice containers in there all the time. As long as the plastic is made to stand the heat of the water, you are usually OK. Home dishwashers have similar restraints.

Ppolypropylene baby bottles (with silicone parts) are sterilized in steam or boiling water.

Very standard at most bars since soap residue will remain on pint glasses and ruin the taste of beer. Instead this just sterilizes them.

Exactly, even friction with hot water will definitely do some level of washing. You can't really estimate the effect of dishwasher detergent until you actually try with and without (which is akin to using placebo for drugs).

The same is true for washing machines in laundry, running them without detergent will still remove some stains.

Once a month or two I run my washing machine on a hit wash with just a couple of old towels in there to 'clean' the washer. You will be amazed how soapy the water is. Running a hot wash like this gets rid of the detergent that is trapped in the machine and removes smells.

I just run every single load with a single "extra rinse" cycle, since I hate leftover detergent/smell on my clothes (and I already use "fragrance-free").

With the extra rinse, I've never had any kind of buildup of detergent in the machine. I know this because I wash my shower curtains with just water and bleach every ~month to remove mildew, and there are zero suds.

I have hard water so washing machine and dishwasher get limescale. I just run them on a hot cycle with a bottle of white vinegar every month or so. Leaves them sparkling clean. Same with the kettle. No need for nasty descaling products.

Many machines have a cleaning program to do exactly that. Machines without it should be avoided IMO.

To be fair this is what I do, I always make sure everything is in the dishwasher less than 30 mins after I'm done and no issue.

Then again I have one of those small half size ones that look like a cabinet door.

I do this with the same set of plate(s) and utinsils and rice cooker it's great.

Granted, I cook daily for myself, and I steam everything and avoid oils/grease in general with chicken/fish.

But it's possible, the only issue I have is hard water stains but better than scrubbing it with a sponge.

We experimented with several solutions (as we found the tablets expensive and needlessly complex). We tried with our own home-made baking soda solution. It worked generally well, except for something like tomato pulp. You'd simply still see it afterwards (red). We gave up after a while, and found a relatively cheap and good brand of tablets. YMMV.

If your kids do the dishes this is essentially the amount of diligence they provide. And people don’t get sick.

I do put soap in but he few occasions I forget I don’t worry and put them away anyway.

> I just don't find it credible that "the results are identical". Either the author isn't paying enough attention, or else they're doing extensive "pre-washing" of their dishes before loading them, or they're washing so incredibly quickly after eating that food never has the time to dry/harden in the first place.

They run the washer many times per day... al the food is probably still fresh and not dried up and hard to remove. Same is true for professional/restaurant dishwasher, where dishes are put inside immediately and washed in a few minutes.

I worked as a dishwasher at a restaurant -a couple differences between the dishwasher there and the one at home- it had a couple tanks of liquids (once for the cleaning cycle, a different one for the rinse cycle) - and the water got seriously, seriously hot at high pressure. Also - still didn't work with baked on spaghetti - still had to clean those by hand.

Commercial dishwashers also don’t hold much (at least the single rack ones in most restaurants) and have much higher pressure spray.

Commercial dishwashers often don't wash dishes - that isn't their purpose. Most often, you need to rinse off any solids and scrub off anything baked on (which happens, especially with buffet-style inserts). After removing obvious dirt, they go into the dishwasher, which realistically is there to sanitize the dishes. If you don't have this, you generally need 3 sinks so you can have a sink full of disinfectant.

You're underestimating the power of steam, hot water, and surfactants and overestimating the power of enzyme cleaners. You could run a dishwasher on fresh dishes without any detergent at all and there's a great chance they'd come out spic and span, though with water stains.

Was curious about this, so I looked it up. Sounds like it's usually bacillus protease and amylase, to digest protein and starch, respectively.

As another commenter mentioned, Dawn dishwashing liquid, used by the author of the article, also includes protease and amylase.

> Everything I know about dishwasher detergent is that it is formulated to clean chemically, i.e. with enzymes etc. that actually break food down over the course of tens of minutes or hours.

This may have changed recently, but dish soap used to have enzymes too.

Dawn still does:

https://www.pg.com/productsafety/ingredients/household_care/...

In the article they claim to run the dishwasher twice a day. No time for sticky foods to become extremely dry I guess..

We do this on occasion if we’ve run out of pods, it recipe calls for some salt as well. It works INCREDIBLY well.

Maybe the baking soda emulates some of the mechanical action of manual washing.

>I run the dishwasher twice a day usually during the week

yep