The Hangout: Makenshi is bribing EP's children with candy. Watch out!

[Azruelli]

Trouble is, I have over 700 Dreamcast discs I really hate the Sharpie writing on

I've never tried White-Out (Or Liquid Paper as it's also being called) on a disk before, But if it doesn't damage the disk and get all plastery like it often does, it might be worth a try to smoth over the writing and go over with the CD writer.
Or you could try wiping the writing with a damp rag-Though I'm pretty sure some damage might be done to it.