Well like Preddy said and what I've read was that your clutch basket can get these gouges in the basket dogs, which will cause the clutch to feel rougher when shifting, so to remedy the wear your susposed to file down or replace the clutch basket so that you have smooth edges again.
Your not removing much material at all. You'd seriously be hard pressed to measure it, your taking off such a small amount. If you look at the pictures I removed JUST enough to take off the grooves, even left just a little bit on the bottom. I wouldnt worry about it. I've been using this method for 10+ years with no issues.