you can buy "wiper" things, i think they are called "data destroyers" cant you just break the disc (this will be the cheap, fastest, and easiet method of data wiping,) and go to your local walmart and get like ten or more for less than ten bucks?
you cannot 'wipe' a disk that is not re-writable and write to it again! This is the whole purpose of being for CD-RW and DVD-RW discs.
man what did you put on this disc? lol something you need to hide! crush to a million pieces.