Originally Posted by
DZEC
I often use a DE blade with tape on one edge to scrape of the surface rust before resorting to sanding. Then I go at it with MAAS or Autosol metal polish to see how much of what remains comes off easily. Automotive rubbing compound on a microfibre cloth can also remove the easier stuff. I have used toothpaste or a paste of baking sofa and water and a stiff toothbrush to get at the parts of the tang between the scales.
Whatever is left will require sanding. As stated above, start with the highest grit wet/dry you feel might work before resorting to the really abrasive stuff. Sometimes I find that a Scotch Brite pad can take off some of the rust before I move on to sandpaper.
I have used abrasive pads, brass brush and nylon brush with a Dremel, but you have to be careful not to let the spinning pad catch the edge - wear eye protection and be aware of the “safe zone” so you don't break the blade or send it flying. The Dremel spins very fast and it’s easy to make an error in positioning the blade.
I learned that there is no point setting a bevel and honing the edge until you get all the rust and corrosion off to your satisfaction. You’ll just have to go at the edge again when you are done.