So, how do you get out of the annual visit, without being rude?

I think some churches who do door to door are just working on people who do not want to be rude, and the weak and vulnerable who are unable to say no.

I would not want to 'convert' someone through pressure (and i see even an annual visit as pressure), because i would question the reason's for a person's conversion.
The annual visit is to see if your stand is still the same. Circumstances change, the person may have moved, or had some event over the past year that has made them rethink their stand. It's not a huge visit, all you have to say is that you're still not interested, and you have no more visits for another year.

I'm curious as to why you view one visit a year as pressure? Our instruction is only to preach to people, not to convert, because only Jehovah can do that. I'm sorry if in the past you've had bad experiences with JW's, but we certainly don't go out with the intention of converting people through pressure.

*Everything said with the best of intentions and no offence intended - please don't hurt me!*