I used to travel frequently for business, generally spending 2-5 weeks at a time in a hotel at least 10X a year. I got to know hotel staff due to the length of my stays and occasional returns to stay at the same property several times in a year. I also worked at a hotel for a year when I was in my 20s. I used to carry or buy my own cleaning supplies. I once found someone else's hair in the sheets of my bed. I found nail clippings in the ice bucket. I found lipstick on glasses. I found hair in the shower. I never assume the room is clean because it isn't.