I actually love what my brother did when they came calling at his door. He looks a little like Charles Manson, full beard, long dark hair (no tattoo on the forehead thank god).
He got so ticked off, he came out the front door pointed at both of the little dubbies and told them he was the Anti-Christ and to leave now! Their eyes got as big as saucers and they nearly tripped each other up in their haste to haul ass.
Since then, he hasn't been bothered. Been waiting to try that one out myself.