I actually had a mate at school that used to have the same problem when playing the old Atari. We used to give him hell because he would be 10 seconds into a game and start scratching and fidgeting. Perhaps this is some karma coming back to haunt me or perhaps it's just the water at the local reservoir.
Before starting your game, grab a fresh piece of steel wool. Use it to empty your nose, but ONLY after running it over the rest of your body first to remove all detritus.
That should solve THAT problem, although it may introduce others 
Errrr.... I bet the steel wool would weigh another kilogram when I was finished. I could probably sell it to some strange person on Ebay, we had a guy here recently who paid $1000 for a piece of cereal in the shape of ET!
