For that many bathhouses to stay open and profitable, the answer has to be somewhat more than “seldom at all”
And this is leaving aside the probably way more common “wash with a jug or basin” method.
What reason is there to think they were any more tolerant of being dirty? Do you think jugs and basins and washrags wouldn’t travel outside the cities? Even small towns had bath-houses. And of course, Europe is just lousy with hot springs - take a gander at the number of German/Austrian towns that have been called “Bad” since the Middle Ages (including near Vienna)…And rural people are also depicted bathing in rivers, as well.
In which recent scholarly work did you read this?
If we trust their artwork at all, it seems they were. They were also fucking. And a whole lot of other social activities. But also bathing.
I read it years ago, maybe when I was in the SCA. Sorry if I don’t remember the title of the work.
I also read about public baths after I visited the ones in Bath, England, in 1976.
I wonder if you have any idea how difficult it is for country folk to wash and keep clean. I learned that when I was doing Living History in the '80s. Hauling water home and heating it to produce wash water is a lot of work that would burn up sunlight needed for other things. They may have washed their faces and hands regularly, but they certainly didn’t bathe often.
Neither did the nobility, who stunk so badly they had to cover their BO with powders and perfume while combing the lice out of their hair. They would have smelled even worse if they hadn’t had servants to scrub their butts after they took a crap.
Why do you think the bidet was invented and is still in use today?