Don't Come A Knockin'

I made my Holiday Greetings phone calls yesterday - hey, Sprint is free on weekends - spreading cheer all over the place. While talking with an aunt, she was interrupted by some roving Evangelists knocking on her door. She said that happens quite often since she has a Alzeheimers ridden, devoutly Christian sister living upstairs. These "cult" members must have radar or are just persistant pains in the asses. Short of throwing buckets of water on them, I haven't quite figured out a fool proof method of keeping these so called Messengers Of God from darkening my doorway. If anybody has any tricks-of-the-trade suggestions, I'm all ears.