That would get rid of Jehovah’s Witnesses, but I see little reason to think it was would necessarily be effective on salespeople.

If, for some reason, you’re unwilling to treat these worthless in-person spammers with the contempt they deserve, my suggestion is to remember that “no” is a complete sentence.

No external factor is necessary to “get you out of” talking to a door-to-door salesman. It really is as simple as saying “get the fuck off my property” and slamming the door in their face.