http://www.bdsmlibrary.com/forums/showthread.php?t=650

Here is a good thread about self-bondage. I don't know if you're into it, but maybe this will get you aroused and then there's no way to release yourself... When you finally get yourself free, your arousal/frustration will bring you a good orgasm.

If you like it, try it. Just don't forget to put the knife where you can reach it