I agree with Alex. Just say you aren't interested and close the door. It won't phase them in the least. If you really don't like being bothered, ask them not to come to your door again. They'll write it down and remember it for at least a year.
Having somewhat of a grudge against JW's currently, I'm planning something more like this, "Is it true that JW's discourage oral sex? I like sucking c*ck WAY too much to be a JW if that's the case. Give me the biggest c*ck you can find and I'll suck it! I don't even care who it's attached to. Old guys, religious guys, atheists, young guys...Hell I'll even suck a smelly homeless guy's c*ck! That's just how much I love c*ck. Fvck do I love c*ck! Do you guys love c*ck as much as I do?"
Of course, it won't do any good. But I'll be amused.
