I have quite a few cd's. Some going back to mid 80's when I bought them. In all this time I've never cleaned a cd. Can't tell if they're dirty anyway....they look fine when I take them out of the case. But there could be some kind of dirt layer on them.....just because I can't see it doesn't mean it isn't there. From what I've read I should NOT use anything like Windex.....or Ether or alcohol-based fluids etc etc etc.....as this could damage the surface...... Seems like a very mild water/soapy solution is what I've read to use.... (1) How often do you clean yours? (2) Did you notice any audio difference after you cleaned them? (3) What did you clean them with?