I just had to tell the Jehovah's Witnesses to leave again.

Maybe you should get a welcome mat that says "Welcome, unless you are a Jehovah's Witness...?"  

BTW, yes we do get our fair share of JWs on my street too. In addition them, there is also one particular lady who, although does not go knocking door-to-door, does do something that is almost as annoying to proselytize her own particular faith (Falun Gong): Whenever she's out & she sees people, she immediately shoves pamphlets for FG right into their hands. Sometimes she does this, even before she says 'Hello.' One can be on their way to the bus stop to go to work or whatever, & really do not have time for this, & yet has to wave your hands "no" at her to let her know that your not interested.

No, natives would give these people fresh meat to proselytize (of course, they could be used to decoy them away from proselytizing to you).

Yep. That was just last year.

As most of you know, I am really naughty sometimes.

I am considering going up to the JW's who set up camp with pamphlets and uber boredom at my bus stop,

and declaring loudly 

"MY RELIGION told me that Judgement Day is actually tomorrow. Armageddon is happening on Tuesday so I think you had better go home and prepare!"

I was a bit surprised when I found JWs had a fairly strong following in Britain, I thought it was mostly an American thing. In fact all the most famous JWs seem to be black Americans (Michael Jackson, Prince, Eddie Murphy, Serena Williams)

I actually called the police (the non-emergency line) and asked what I could do within the law. The cop I spoke to said that if I posted a "Private Property, No Trespassing" at the base of my driveway, I could call 911 if there were 'trespassers" on my porch. Since I have a fenced-in garden outside my front door, I put the sign on the gate from the driveway, and added a chain and snap hook. My dogs can run in the garden when they need to "go", and their barking is also a deterrent.

So far, so good, but they could still leave a pamphlet stuck in the gate.

Try to remember that the JW aren't just a church.

Oh no, they're a public service organization too! 

For Toasted Cheese, OldSamVimes, or anyone else, that MIGHT be interested in challenging JW belief, if & when they come to proselytize, this Catholic website offers a brief synopsis of their beliefs"

Incredible Creed Of The Jehovah's Witnesses

Actually, you should invite them in and proselytize to them, but for the fact that if they got sexually unblinkered you'd probably never be able to get rid of them, and having to repeatedly hose them down in the driveway could be a little unsettling for the neighbors...