Hmm. I don't want to seem too skeptical, but 1/100th of a mm doesn't seem like it would make a tremendously appreciable difference. He put an awful lot of grease between the bushing and the blade that wasn't there before, and then he used even more around the washers themselves. That seems like it was the cause of the enhanced smoothness to me.
I would've liked to see a comparison against a similarly lubed but not modified Sebenza. Or maybe one where he lubed and stropped the washers but didn't remove any measurable amount of material.
Still, whatever the actual cause, he did make his Sebenza a heck of a lot smoother!