Great advice, TWR
We live in a quiet little cul de sac by the sea here on the south coast and we have some lovely elderly neighbours amongst them. We always look out for them and most have "NO COLD CALLER/NO SALESMAN" signs on their property, but we tell them that if someone ever calls, and is a bit pushy/wont leave, to ask them to wait a moment at the door and to phone one of us quickly and we will go and see what exactly they want and who they are.
We have seen off and reported many pushy sales people in the past and it seems word has got around, as we appear not to be ever bothered just lately.
Happy days :0)