Hmmmm I wonder if putting that horrible tasting stuff or cayenne pepper on your finger would discourage that urge ( hopefully not make it worse). It takes time & not doing something for a longer period on time to program a behavior out of the mind & reprogram it with positive behavior.

I would find something good/positive to distract myself with every time the thought popped into my mind....watch a dVD you really like....good distraction for several hours....or get involved with a craft like knitting or painting that uses your hands in a positive way....just some thoughts