Read the first post in this thread and the linked tutorials.

http://straightrazorpalace.com/showthread.php?t=8604

You obviously have to be careful with a dremel due to the high RPMs, but Satan's tool they are not. I tried out the technique from above and it works great. It took far, far less time to go from the medium abrasive buff (280 or so) to 400 grit than by hand, and I could still move my fingers afterwards. The scratch pattern will not look as uniform as handsanding, but 5 minutes of handsanding will straighten that right out. You can take the blade from start to as high a grit as you want to go, then do one quick handsand.