I think what you are asking for is basic hygiene. I personally couldn't cope with someone not using house slippers and separate toilet slippers. I expect that from anyone who visits me, but its also the norm in my culture. Walking barefoot in the house/toilet and then getting in bed is just gross to me. To be honest, I don't think you are asking for much. I don't allow outisde clothes indoors either and I expect my partner to get changed into bedroom clothes, so no lounge clothes in the bedroom. I also expect my partner to wash his feet & shower as soon as he gets in the house and change into indoor lounge wear
I have never heard of any of this. We are barefoot in the house, due to comfort, not because we don’t allow shoes. If someone comes home and is going out shortly, they tend to just keep shoes on and we never make visitors take shoes off. We do generally wear slippers in the house in winter but that’s because our feet are cold. If we have to do a quick duck out to pick someone up, collect a package etc, we just do it in the slippers as who could be bothered to change shoes?
outdoor/indoor clothes? Showering when you come in? What? Is outdoors radioactive or do you encounter acid rain or something?
Honestly, I’ve seen sick people for decades. Never, ever, come across anyone where the cause of any illness was a weird set of rules regarding shoes/feet that had been breached, weird rules regarding indoor/outdoor clothes that had been breached, or because they ‘only’ wore undies and not shorts to bed🙄. I can guarantee absolutely none of this has caused illness in a person, and is not ‘dirty’. I’ve treated ‘dirty’ people, that’s completely different and usually they are homeless, severely mentally ill, or elderly without physical capacity and lack of social care. But someone who doesn’t have a complicated set of indoor shoes and indoor/outdoor clothes, nope.