One of my roommates, back in my first go at grad school, was from Nigeria. One day he and his friends were getting ready to go to a local church and talk about his country (and I must point out that they were all good Lutherans). Dressed in his regional dress, he opened the door when a Jehovah's Witness rang the bell.

He stood there and politely listened to their spiel, and when they asked if they could come in a talk, he replied, in his perfect Oxonian accent, "Certainly. We are just getting the goat ready for the sacrifice and you can help hold it."

They left, and we weren't troubled again.