A while back I got a ton of games at the flea market - one of them was We Love Katamari. The game plays fine, but it doesn't have music on some stages (or the music just ends at random).

After inspecting the disc, I noticed it had something like water spots on it. I'm not sure how to clean these up; I'm afraid of using alcohol because the disc may warp or something. And tapwater... well, it's not exactly safe for any sort of usage.

What can I do to get these cleaned up? Any suggestions? Are there any special wipes I can buy somewhere that won't scratch the disc?