Having trouble with some of the commercial burnishers, I researched the hardest metal and came up with tungsten steel. I bought a short rod of it on the big auction site, added a small dowel handle on each end of the rod and now have the best burnishing tool yet. It has finish sharpened many scrapers, most made out of commercial saw mill band saw material, and not a scratch on the burnishing tool to date.
Great video. Dean Torges used and taught the same method.