Well, I replaced mine this weekend. I did a trial and the motor consistently spun in one direction. The one I have is about the cheapest on the market so it might not have that fancy reversing feature. I'm going to strip it down this week and see what I am working with. It smells pretty foul. Hopefully I can remove the nasty pieces and still have a usable motor.

I like the idea of a shredder, but the disposal design is more like a blender. I could use the motor to power a homemade shredder though. There are a couple guys online that built plastic jug shredders. They look like oversized paper shredders. I have an ever growing stash of HDPE jugs that I need to do something with. Right now it is too time consuming to break them down by hand. If I could reduce the time to process, it could open up all kinds of possibilities.