I had them round about 3 weeks ago - when I said politely no, having listened for a minute or two, I got a sob story about what a terrible day he'd had, and I was going to make it worse. He wasn't easy to shift. If this is a genuine cause I'm with Spooniferous - the goods have to be reasonably priced. With a seven quid cloth they're asking a quid for a cloth and a six quid donation - which is quite a big donation for any charity you randomly encounter, as opposed to one you have decided to support regularly.