In the UK, we have an automotive product called 'T-Cut', removes the 'dead' outer paint layer, seems to work pretty well on scratched CDs.
Hi. I have repaired probably over 100 cd's by now. I started with a " disc doctor " product and it worked very well for lightly scratched discs.But I was still having trouble with heavier " yard sale " cd's. So I adapted the disc doctor system as follows.Go to an automotive refinishing store and get some 1500, 2000, and 2500 grit emery paper. If they have 3000 or 3500 this will help with the final polishing.Make a little sanding block from styrofoam or stiff rubber. Something like 5cm by 3cm is good. Cut the emery paper into strips that fit the block.Place the disc on a flat hard surface and wet the clear side with clean tap water or distilled water. Sand crossways with light pressure, 1500 first, then 2000 etc.The cd will now have a milky appearance on the reading surface. To finish, buff hard with a small piece of felt.The whole process takes about 5 min per cd.Generally, tracks go from being unreadable to near 100% quality, as read by EAC. If you can find 3500 grit paper, the final buffing can be done with a soft kleenex with near perfect results.