You don't need to do threads about that stuff dude, it only gets people jealous.
Anyways, frankly I'm much ruder to salespeople than many of you guys seem to be. I tend to simply say "not interested, thanks" and shut the door, hag up the phone, whatever.
You also have the strategy which my mom does a lot and that is to tell everyone to be quiet and hope the person walks away. I mean I could do that as well but for some reason when a door knocks I fell compelled to open it. I always want to know who that person is. Maybe they are bringing good news. I think I would even fall for the SNL walking sharks if that was a real thing.

Jason