I don't think the premise is bad, but we're pretty good about separating REAL consequences from contrived ones.

Example:

Several years ago, I put a $100 bill in five different envelopes (w/ no return address)... all addressed to a guy I really, really dislike. I gave the envelopes to my housekeeper and told her that every week, we'd measure my weight and compare it to the previous week. If I didn't lose weight during the week, she was to mail one of those envelopes. It worked for 2 weeks, but then I gained 1/2 lb during the 3rd week and I pleaded until she handed over my envelopes.

I think there might be a workable hack here, but it takes courage to make the consequences real and irrevocable.