I agree on this, I previously didn't interpret the showering as a cosmetic action, but see that this line of thought would make sense now.

To your aside of health benefits of showers: I also tried to research this, but other than getting rid of contamination (hazardous elements e.g. during construction or demolishing, or just dirt on wounds) I couldn't find any serious claim that washing the skin is beneficial for health (outside of making sure hands are clean before touching food or mucous membranes), I just assumed there should be one.

I take my confident stance on this back...