Start counting.
That is a Japanese knife honing guide. It clamps on the spine of a knife to help you maintain a consistent angle. Great if you want you razor blade to be robust enough to cut paper, which he did.Doesn't know what he's doing with razors. Start counting indeed! Whatever the heck that contraption was that he had clamped on the spine during honing was, it looked to be thick enough to produce more like a 30° included angle on the edge. Most of the honing and stropping strokes didn't fully cover the edge from heel to toe either. Also during stropping he didn't have the spine on the leather. Hope nobody paid money for that "restoration."
Ouch on lots of levels, but I have to say he did a nice job on the blade clean up
I though of that as well, only with 12% vinegarTrying not to be a conspiracy theorist, but I find it hard to believe that the blade in the first picture was without very deep pits and turned out pristine. I have tried to bring back blades that weren't nearly that rusted and couldn't possibly remove the pits. Just thinking out loud.