He quite calmly said, "Hello, can I help you?" with the door WIDE open and feet shoulder width apart. LOL
The next time they showed up he talked their ears off telling them crazy scary POW 'Nam stories... every time they tried to politely excuse themselves he would start a new story.
They didn't show up very often... I think at some point our house was put on some sort of "don't visit this house unless you'd like to imperil your immortal soul" list.
Here they always send underage kids... you can't do anything fun to run them off.