You shouldn't threaten your roommates.
Paul's roommate leaves his dirty clothes everywhere in the room.
Paul wants his roommate to stop leaving the room a mess.
Paul asks his roommate to pick up after himself and offers to help.
Paul threatens to get his roommate kicked out by the police if he doesn't pick up after himself.
His roommate slowly learns to keep his area clean.
Paul's roommate steals some things out of spite while Paul is away and leaves the apartment.