Al Padrino

Hi, not quite sure if this sort of thing's been posted (although I'd have to think that it has), but I was just wondering how often do you clean your DVD player and what do you use? The reason I'm asking is that I can't remember the last time I did, and lately, my discs have been freezing up every once in a while. At first I thought they may just be defective, but they were all brand new and when I took the disc out and played it again, everything was fine. Any tips?