OK, let me know where you are and I'll come and use your shower!On the other hand why would you bother getting dressed for a cold or wet walk across a field and then get undressed in the usually cold verruca infested shower and get dressed again to walk back in the cold or wet. Much quicker easier and more pleasant to just take off our pyjamas in our warm motorhome, step into our warm clean shower that nobody but us has used, do the business them step out again towel dry and get dressed in your day clothes. And no, we do not use site toilets either.
And all of that is even more important when you consider the times we are living in. I certainly would never use a shower or toilet that I know somebody else who I do not live with has just used. Covid has a 3 day life span outside the body and I do not want to take a lottery as to whether somebody carrying it has used the toilet or shower I chose.
As for cleaning down the shower after use we just spray the walls and door with Mr Muscle Shower Shine and just leave it to do its thing.