Isn't it crazy how that one awkward minute ruins your whole day? I used to try the nice way, just saying "please be careful" and hoping they'd listen. After the third time someone tracked prints across a wet coat, I realized Brian572 is totally right. You have to be a human wall in the doorway. It feels rude, but letting them through is way ruder to the next person who gets a ruined floor.

It's funny how common that is with household stuff too. My neighbor's cat still hides from the vacuum cleaner after five years, same panic every time. They just never learn some sounds are harmless.

Seriously though, it's just a word choice. Like, jamie_taylor's laundry office is clearly a joke. Maybe your landlord doesn't mean it in a bad way, you know? It might not be that deep.