After having been to swimming pools and hot spring spas in various countries, I wonder what people from various places think of it?

My first thoughts/observations stem from France where going to thermal baths means:

1) having to wear real bathing suits and not (mostly applying to men) shorts

2) having to shower before entering the pools - (some places make it tricky for you not to shower). There's some one checking or at least the entry makes you shower (motion-activated shower walkway in some instances)

Of course this doesn't seem to make a difference in some places. I remember going to a hot springs in the Pyrenees where the water had a film of oil) on it. Not sure if it was body oil but I've never observed it anywhere else.

In Iceland (at least at the Blue Lagoon), bathers are required to shower (as one would in one's bathroom) with soap/shampoo before entering the pool. Of course there is still hair and other grime in the pools (embedded in the clay).

In Japan, onsen bathers make a very public ritual about body cleansing before entering the pools.

In Italy, I don't remember the bathing rules but swimmers have to wear swim caps at least in some places (Cavalieri in Rome for one).

In Thailand, Malaysia and China, there are signs asking swimmers to shower before swimming but it is a mere suggestion, it seems.

In BC, Canada, the hot springs (3 commercial ones I've visited) require bathers to shower but not everyone does this and it is not always enforced.

I noticed that for hotels in BC and in California, pools/hot tubs have no place to shower by the pools. In the last few days at a Palm Springs-area hot bore water resort, it appears to be a free-for-all as far as bathing suits go for men: sport shorts, surf shorts, underwear, long underwear loose boxers, cotton shorts. Not much better at a somewhat-upscale hotel on the coast south of S.F.

I like the idea of showering before entering the pool (will always do that given the option) and also wearing real swim wear but this seems to go against the grain in North America.