I sympathise, Simons Mith. Some years ago I seem to have stumbled across a method of reducing/eliminating nuisance calls from the Mormon bretheren. I had a shop at the time. A couple of their 'missionaries' came a-knocking in an endeavour to sell me their wares. In a shop, for heaven's sake! Anyway it was a quiet day so I took them on. An hour or so later, with only a few short interruptions for customer attention, they left - leaving me with a copy of The Book of the Mormon (interestingly sub-titled Another Testament of Jesus Christ) and a promise to pop back in a few days to give me time to have a look through it. They did not return. Disappointing in one way, most pleasing in another.
Luckily for me Bigsmith Towers is equiped with a large forward facing bay window, so (during the hours of daylight at least) i can see the buggers coming. This gives me the time to dust off and cue up a bit of good old death metal - something like Venom or Cradle of Filth - strip to my underpants and answer the door with can of Stella in hand. They don't stay long....
What's their success rate like, I wonder? It strikes me that anyone vulnerable to this sort of thing would have succumbed years ago, and then would sell out to the Mormons and so on as each came round in turn. If their success rate truly is zero, WHY DO THEY WASTE EVERYBODY'S TIME DOING IT!?
I've often wondered about that myself, Simons Mith. After all, if my forebears are to be believed, even the tramps used have a 'secret' code which they scribed before someone's dwelling to indicate 'Probable', 'Possible', 'Unlikely' and 'Don't go in there the dog will eat your balls and dump your remains in the bin'. Then again, most tramps are probably better organised (and intelligent?) than those of whom we speak.
I live in a student house, and it was a student house for many years previous. I think they've learnt that we have absolutely NO surplus money - it all goes to tescos or over the bar. and I generally tell jehovah's witnesses I'm jewish. gets rid of them.