Okay, I'm getting a Macbook soon, and have a few questions. I have a friend that got a Macbook about 6 months ago, and the thing is DISGUSTING. his palm rests are almost black, and I can't even stand to use it. Does this happen to every Macbook? Is there a way to prevent it? If not, is there an easy way to clean it with absolutely no risk of scratching the laptop?