Now and again a travel writer does the world a real service, and Rick Steves has done just that, with one of the most sensible, straightforward articles on The Toilet Problem when travelling in Europe. What caught my eye was his puzzlement over blue toilets in Bern, which I haven’t encountered myself, and his comment that the blue lights discourage drug users, who can’t see their veins there. No idea if he has a good source to back this up, or if it’s just his own travel-savvy assessment, but it made me read the rest of the article, which has sound advice for travellers anywhere.
I don’t know about your mother, but mine was a lot like his, always suggesting that we should use “the facilities” while we were in a place because you never knew when you’d find them again.
The only thing I would add is that in my 25 years in Switzerland I have rarely found a cafe or restaurant that objected if I asked if I could use the toilets. And gas stations usually have them outside, and are happy to give you the key if you ask.