I tried the Blue Diamond spray from Dave (1 micron) on Balsa and I gotta say the results blew my mind.
I only did about 4 very soft passes on each side on already pretty sharp knives that for example aced the edge tester gadget..
Still, it took the edges to another level: really made the edges just about perfect, an interesting combination of toothy for things like tomatoes and polished for everything else.
Does anyone know of pictures that show what is happening at the microscopic level with 1 micron diamond? My 40X magnifier isn't nearly good enough to detect what is going on.
I also wonder if the effect of the diamond's (small in this case) yet irregular shaped crystals approximates the magic everyone talks about with high grit natural stones, you get very very tiny microserrations combined with what visibly looks like a perfectly polished edge...