I've noticed through experience that you can't clean Dreamcast games same way you clean other games of it's generation. I had a copy of NBA 2k1 that would play normally for five or ten minutes but would go into the Dreamcast menu. I used a CDdr it a couple of years back and made it unplayable. (Stupid me) I have other DC titles that aren't in the best condition. I want to know is anyway to clean them properly or is this all on account disc rot I've been hearing about in other forums.
CD Doctors fix scratched games by turning them into scratched discs. I've used one when I was really young and it destroyed the disc Your best bet is to go to a local game store that does resurfacing. There's one about 20 minutes from me that does $2 a disc. Unless there's really deep gouges the discs are pretty much in new condition after But this should probably go in the repair and restoration board rather than development