Cdr-erasing, and true blind-writing



Just a couple of hopefully quick questions. The first of which if pretty simple - anyone know of anything designed to erase parts of a multisession CD-R (i.e. corrupt the relevant bit of the TOC and the previously written data)? It would be quite use ful for me, as there are several CD's of which most of the stuff is fine, but some have obselete and confidential information on them, which I'd like to destroy without taking the rest of the CD with it...
Secondly, does anyone know of a true blind-writer? That is, a program that will force a CD-R drive to write regardless of whether there is a recognised CD in it - I have a CD-R that refuses to recognise those shiny CDs (no printing, blue-ish backs) regardless of their capacity or presence. A blind writer would be particularly useful in this situation, but I have yet to find one.