Kitchen sink

Don't see why not. Even if it's dirty and got "germs" on it, the high tempeature eg 70 deg C and the large amount of water should both get it clean and avoid contaminating anything else.

I thought that. It has a 'rubber' seal but I assume this is designed for boiling water. I suppose if I'm concerned I could douse it with boiling water first.

Is the chain long enough to reach?

(OK. It's fine.)

Will the chain be long enough? As it happens I was once told by someone who did reports on the hygiene of premises like hotels that turning the washbasin plug over and seeing how clean it was on the underside was an indication of how detailed the cleaning regime is, of course many basins you now cannot as they have those lever or knob worked ones. Unfortunately they are often poorly maintained and are broken or don’t seal well.

GH