hehe... Sorry, it just reminds me of some fun we had with a buddy the night after a big party many years ago. He had the same problem, and was desperate to get rid of it before his parents saw. We had him doing all sorts of dumb things to get rid of it! A cold spoon, cold raw fish, standing next to a microwave with his neck exposed, and many many others.
We finally showed some mercy and stopped, but not before he spent a good two hours with globs of toothpaste on his exposed neck to "draw the hickey out".
Honestly, a hickey is just a bruise, and there is pretty much no way to get rid of a bruise other than time. Really, the only thing you can do is mask it...