I worked in car sales for a decade and a decent 10%+ of salespeople IMO would get aggressive to your face over that.
Or do you only say that to the non criminal looking ones?
It's basically WarGames. The only winning move is not to play. I don't answer the door when I'm certain it's a salesman. I don't make eye contact/respond to the ones that are setup outside of a store. Same with the ones setup in malls/stores (looking at you, Costco).
Personally I enjoy a bit of excitement, but most people don't want confrontation, which is why appearing confrontational before they're committed works for making them do a u-turn quickly.