I've been thinking that an effective way to expose the idiocy and vacuousness of JWism is to use it right back on them when they come to your door.
Say you're a fader and you've moved to the territory of a different circuit where the JWs there don't know your JW background. When they come knocking at your door, just put on the JW mindset and pretend to yourself that the JWs at the door are not JWs but members of a "false religion."
When they offer you literature, you tell them something JWish like: "Sorry I don't accept literature of other religions. I don't believe in interfaith."
When the JW says it's all based on the bible you say: "Well, I know for a fact that my religion is based on the bible and I have the truth, and since Ephesians 4 says there is only one faith . . . your religion can't also be the truth and so I can't accept your religion's literature which contains false religious lies -- no offense."
Let's say you tell them you're a Catholic and they start mentioning the Catholic pedophile scandal that was prominent in the news a few years ago. You respond by saying: "These are just satanic lies by our opposers. You can't believe everything you hear in the media."
If they point out the unscriptural catholic teaching of purgatory you just tell them that catholics no longer believe that -- that the light of truth gets brighter with time just as Proverbs 4:18 says and so even if there might be some errors in current catholic teaching, God will refine the understanding of the church in time and so you will not be disloyal to God's catholic organization by leaving the religion just because of the errors of imperfect men of the past."
If you say you're a catholic and one of the JWs at your door say they used to be a catholic, you can say: "You're an apostate! I don't want to hear anything you have to say! You're only here to draw me away from serving God as part of his earthly Catholic organization!"
By now you get the drift. When you use JW reasoning to counter JWs efforts to preach to you, you either force the JWs to confront the idiocy of their own reasoning (if the particular JWs at the door are smart enough to see the similarity) or you force them to argue against their own reasoning in an effort to try to reach you. It's a lose-lose situation for them.