1. Answer the door naked and carrying weaponry. (immediate results)
2. Pretend to be the slowest talking person in the world and see how long their spirit of charity lasts.
3. Answer every one of their questions with "What do you mean by that?" This might take a while, but you and your loved ones can have fun placing bets on how long it takes for them to get flustered and leave.
4. Ask them to reconcile Revelation 1 and 22 for the "Alpha & Omega's" identity (Jesus or God), repeat constantly. You may have to resort to another method to actually get rid of them, but this will definitely make them sweat.
5. Excuse yourself from your sitting room (or wherever) ...and don't come back.
6. Make a series of increasingly reprehensible fake phone calls. (booky, order for pornography, drug deal, obscene call, and if they are STILL there, a tearfull confession to the police for the murder of the last Witnesses who visited you.)
7. Pick an oft-repeated word in their lexicon (God, Jesus, heaven, it, the etc.) and giggle whenever they utter it. If they ask you what's going on, say "nothing, why?" in very even tones, and giggle again.
8. Same as #7, except say "beep" instead of giggling.
9. (males only) Feign an intense interest in their speil. Part way through, begin putting on make-up, hosery, a dress, the whole works. (make encouraging noises [uh huh, I see...] throughout and if they ask you what you're doing, pull a #7) If they're still there when you are done, Ask them if they would please kindly leave as you have a hot date in ten minutes.
10. Look smug and tell them that your God can beat up their God.