We have a sophisticated alert system at my house. My mother is incredibly nosy so she's almost always looking out the window trying to see what people are doing with their lives... so when we have the religious door-to-door people coming around, she knows. She then alerts whoever is in the house and near a window to hit the floor and she rushes to turn off the TV so there's no sound and they can see nobody - then when they ring the doorbell they can legitimately think nobody is home rather than feeling dejected that there are people who are just refusing to answer haha.
Though one time I was home alone and I opened the door and there was a man who looked like some sort of church-appointed converter standing there with a Bible and a booklet he handed me, and then next to him there was a wholesome-looking family (a mother and her two adorable half-Asian children) that he had obviously been assigned to stand there to be psychological faith-candy and show you how wonderful your life could be if you went into their religion. I was so taken aback by this obvious ploy that I couldn't even bring myself to slam the door in their face. I opened the screen door and looked on in amused astonishment as this whole pimped-up scene unfolded before my very eyes. One of the little half-Asian boys - the one old enough to be out of a stroller - ran up to me and excitedly handed me a flyer and asked me in his cutest voice if I'd come to their next meeting for new members. Then, after the man had finished grilling me about what I think of God and telling me in this oddly seductive voice (seriously, he was a pro. Had I been at all questioning my beliefs I would have fallen into the trap) what God could do for me, I promised to be at the next meeting, took my flyer and pocket Bible and shut the door, stunned. It took a good ten minutes before I could even register the incredulousness of what had just happened.
Just to clarify, I didn't actually go to the meeting and never had any intention to do that lol. So yeah, that's how I deal with Jehovah's Witnesses lmao.
My extended family however, are very different. My atheist uncle calmly and sweetly with two elderly women until it was very clear they had no clue what they were talking about, whereas my mother's cousin opts to answer the door completely naked and time how long they stay after that lmao.