Is a crossbiter someone with dental problems 
This is starting to get like that old program "Call my bluff", waiting for someone to say it derived from some French word XYZ...........
As the OP says most scams have been going for centuries, I guess what worked then still works now as it relies on human nature however knowing that this scam exists i'd like to think i'd tell the bloke to Fuck Off and point out I knew it was a scam, unless he looked big and hard of course
