I *may* have discovered a way to deal with mine. The first time they came I was too shy/polite/wishywashy to stand up for myself, so I meekly allowed myself to be handed some literature and read a bit of Psalms on how the earth will never be moved, hence (apparently) the Apocalypse will never in fact occur. I did venture a feeble objection at this point, but the woman was incredibly old and frail and tiny, so when she said 'No, that's all metaphorical' I felt it would be like kicking a kitten to push the issue further.
But the next time she showed up, I was in No Mood because my Catholic mother-in-law was about to show up, and I didn't think I could handle a JW-Catholic-Reformed Baptist threeway without ushering in a little personal neighborhood Apocalypse. So I listened in a vaguely agitated way while she exposited a bit more Bible at me, until she said something about free will.
Me (thinking 'Smokering, are you a man or a mongoose?'): Ah. Actually I'm a Calvinist, I don't believe in free will.
She (puppy dog eyes): What?
Me (thinking 'Great, now she's going to fall and break her hip just to make me feel bad'): I don't believe in free will, I'm a Calvinist
The other woman, a girl about my age and fortunately more robust-looking: Oh, what's that? I haven't heard of that.
Me (taking a deep breath): Really? Well, it's kind of the opposite of Arminianism. it's the Reformed position. You know, um, Calvinism as in John Calvin; total depravity, unconditional election, limited atonement, irresistable calling, perseverance of the saints--
They were scuttling down the drive just as MIL got out of the car, and I haven't seen them since.