I can see it working, though. And I will do that when I have kids... if I see much of them... hrm having kids and being a surgeon could be difficult... Meh, who knows I may not get into med school.
But really if you learn about reinforcement and punishment and you properly use both (messing up either is fairly easy and constantly done by everyone) you can mess around with your kids so easily. My psych teacher was telling us about how she taught her kids that Halloween was about running around getting candy for her and that if they got a good haul she'd give them each a piece. It took them until the second grade to realize that she was messing with them.