So i noticed that my bottom of my new macbook started to get quite dirty. mostly from hands and not surfaces because I clean all the surfaces before putting down my computer... ANYWAY, I thought I'm gonna try something different than iKlear. I grabbed my make-up remover. NOT to mistaken for nail polish remover. Make-up remover doesn't have any harsh chemicals. and OH MY GOD, it worked so well. So use make-up remover on a soft cloth or cotton pads, that's what i use, to clean your bottom case! I would like to hear what you all think of this... I've been doing it since about a week after getting my Macbook. The only spots I cannot remove is the the four corners. I don't think there is away around those pressure spots.