Perhaps linoleum (https://en.wikipedia.org/wiki/Linoleum https://en.wikipedia.org/wiki/Linoleum) or some newer material with similar properties? I've used older

Perhaps linoleum (https://en.wikipedia.org/wiki/Linoleum https://en.wikipedia.org/wiki/Linoleum) or some newer material with similar properties? I've used older showers with linoleum floor and it was not slippery at all. Dunno, not an expert in this area, but even so, using polished tiles should be obviously a bad idea to anyone stopping to think about something more than looks.