After living in AZ for many years, I know the missionary tactics...
One day, when my youngest was a senior in HS, he spied a guy in dark pants and a white button down shirt approaching our door. Thinking it was a Mormon, he stripped down to his boxers to play a joke on them and make them think we were heathens. Much to his dismay, it was James Eldridge, a very nice young man, running for state rep. We told him why our son was running around half naked, like a crazy guy and he took it in stride.
The last time LDS missionaries rang my bell, I pointed to the mezzuzah on the doorpost and told them that "if you see one of these, it means the people are Jewish and you probably won't make a sale."