Roommate problem! plz, he is the most irresponsible, dirty person, like a big baby. W r best ways to tell him?

My roommate is a really dirty person. he doen't clean up after himself, leaves the dirty dishes in a sink for two days and cleans it only after i tell him to, and not even right away, maybe like 10 hours later. His room smells like cow maneuver. his clothes are on the floor that you can't even get across the room. Every time i approach him about this stuff he deflects and starts pointing out other irrelevant stuff that is half the magnitude. so, i need to find ways to make him do it, and i don't want to teach him cuz i'm not his mother. If there are ways to make him do it i will try anything. ) thnx