I have no soliciting and no trespassing signs. It has cut down the total number, but has not stopped them all. I come to the door with my shotgun and say "didn't you read the sign?" If they challenge me on it, usually with something like "we just want to help you," I say "get the fuck off my private property" and rack/pump the old Mossberg. They always run away.
I'm not kidding. I have zero tolerance for solicitors; there are signs at the entrances to our neighborhood, signs throughout the neighborhood, and a sign on my walkway. The shotgun thing was especially hilarious when it was my girlfriend answering the door. They were trying to sell us a security system. She said "we already have one. I have a shotgun." They said "well ours is wireless" and she interrupted; "I don't think you heard me," said my awesome girlfriend as she pumped the shotgun and put it on display. They quite literally ran. LOL!
Yes, this is legal. We do it INSIDE our house after already telling them to leave our private property. No, we're not white trash; we just feel strongly against solicitors and have some fun exercising our rights.