Crack the disk open, and superglue a sliver of refrig. magnet over the disk, away from the sliding metal part. Make sure the disk itself can still turn. Then superglue the top half back to the bottom, replace the metal slider, and find a victim. The disk will constantly erase itself whenever it turns. It might damage the drive, but I don't think it will.

Put a drop of superglue between the metal sliding door and the plastic of the disk, so it will not open.

Slide the door open, so you can see the black shiny disk, and put a small drop of superglue onto it. Let it dry, and make sure that it doesn't stop the disk from rotating. When the disk reader hits that bump, it'll rip the the thing right off. Very mean to do.