The guy who invented 'crock sticks' didn't come up with anything the old guys in Big Smith overalls didn't already know about.
This was an old trick of most of the old timers. There was no mystique or hype about sharpening up a knife back then, it was just sort of second nature to working men who may have needed to touch up a knife and they were not at home, and even if they were, there was no super miricle gizmos back then. Coffee cups, top edge of car windows, smooth side of a brick, the long shaft of a screwdriver to act as a steel, lots of ways to get that pocket knife cutting again.
They didn't obsess over it like we do now. Just used what was around, and went on with life.