The easy to remember terms and will work nearly anywhere without giving offence are: "loo" in a residential property or "gents/ladies" for a non-residential property.
I assume toilet hands were an unspoken issue, because there was no possible way to traverse from the toilet room to the washroom without touching anything.
For a complete tangent, I’ll mention that Soviet toilets had a “poop shelf” so that people could eyeball their stool to gauge their health. One flaw of this design is that there was no odour suppression offered by toilets that immediately immerse stool in water.
Still better than a Poseidon kiss.
I think their style is an import from Germany in the first place, but it stuck.
Meaning 1a is the object, 1b is the room. https://www.merriam-webster.com/dictionary/toilet
Restroom, and a variety of others, might be slightly more usage specific but still… wouldn’t be unexpected or weird, I’d say?
I think only people of a very specific upbringing ever call it that here. Certainly nobody in my circles would.