I just finished a really great book called "Drop Dead Healthy" by A. J. Jacobs. In the book he described how he broke a habit of eating sweets. He made a contract with his wife that if he ate sweets, she would send his money to a group he hates. In his case, it was the American Nazi party. He said it completely broke his habit be because even looking at sweets made him think about supporting them with his money, and the thought repulsed him.
I've made a similar deal with my husband, using a different group. If I cheat at all, the check gets sent.
I know I can't live the rest of my life like this, but in the future I'll have the band to help. I'm afraid if I don't do this, I'll rationalize, a little of this or that....