I love to answer the door when they call, I usually let them speak for a little bit and then jump in when they start to pull out the literature and reveal myself to them. Thats when they turn and run. I usually call out to them when they are leaving and say "Tell the brothers and sisters I say "HELLO". I love to see them run!!!
I fill my motorcycle up every morning at the same gas station and they are always there, they approached me once and I gave them the same routine. They stay away now, I just wave at them and gun my bike and pop a wheelie.
My inlaws had me answer the door once and where AMAZED how fast I got rid of them. They asked me "How did you that?", no matter how hard they try they cant seem to make them go away......the awesomeness of being DFd!!! HAHA