Rich:
I've seen a lot of things like that in my life and times. Years ago at my club there were a number of guys who would ask for what they called "The Blue Plate Special" generally on the last hole. If they were down it was an added bet starting them a half stroke up on the last hole.
I was a pretty nice guy in those matches but if I was winning I generally declined that bet under Warren Buffet's adage (which I did not know at the time) to never invest in something you do not fully understand. Or at least that's the excuse I always used to decline the bet! I have learned in my life that if you can foster the impression amongst some people that you are fairly stupid it can and often does work massively to your advantage!
Years ago I used to play some pretty high caliber backgammon and occasionally I would run into these yahoos who would try to play me double or nothing. Only problem is they kept asking for it over and over and over again. So I just played dumb and said something like I wouldn't agree to that or if I did only one time.
I might have even tried Pres. Bush's malapropism of----"You can fool me once, but if you try to fool me again, uh, fool me twice, uh, uh, fool me, uh....well, shame on you."