I have some small DMT "stones" that I use for sharpening corner chisels. I agree with Dave that the waterstones are a pain as they need to be flattened. They're also expensive and messy. We use the old sandpaper method for chisels, slicks, planer blades, etc:



Just a big piece of plate glass with 9 different grits of sandpaper mounted with spray adhesive. Grits are from 220 up to 2000. You get the finer grits at the auto parts store, they use them for auto body paint. Since there are so many grits, you don't need to spend much time on each one. Just a dozen strokes each on the front and back, then move to the next grit. If they tear or wear out, just glue down another 25 cent sheet. A lot cheaper than 9 waterstones. Our station is always set up next to the Tormek, so it's really easy to freshen up your edge. CB.