You're at home one day when there's a knock at your door. Upon opening the door, you come face to face with Bruce Springsteen. "Hey, I don't mean to inconvenience you, but can I use your bathroom? I just happened to be visiting my friend next door when the 'urge' struck me and I'm afraid I can't hold it much longer. May I?"
Let's say he talks you into letting him use your john. When he's done, he comes out and thanks you and he's on his way. You inspect the bathroom. The 'Boss' took a big dump in your toilet and didn't even flush. What do you do?