I've sanded the heck out of these things and all I've gotten is 'plastic dust'. What I'll probably do with this is run it in a small set up with some white clouds or maybe just rotting food and plants for a long time and keep an eye on it. Then I'll get everything in check water quality-wise and add a few shrimp and snails to see if there is any hidden toxicity from the DVD's. Sound like a plan?