Handwashing Technique Is Surprisingly Controversial

Don't play games with this. Buy a good quality surgical scrub brush and use it regularly. They are not inexpensive, but they last a long time. You can usually buy them locally from a medical supply store. When I worked in hospitals, we always washed with a surgical scrub brush.

I also imagine the appropriate times to wash hands means there is no tap and soap or accessing these means increasing exposure.

We don't work in hospitals.

At home I see little point in washing hands, once covid-19 is in the house it's to late.

It's more important to stop it before it enters the home.

Some caveats, after unpacking groceries etc and obviously salmonella and everything else needs to be reduced atm.

The point of washing for a relatively long duration is to to make an excuse not to do cursory or no washing at all.

Part of the technique is a distraction to justify the duration.

And yes, to try to cut down by a few orders of magnitude.