20 laps doesn't seem like a lot for natural stones but I applaud what you are doing. I have done the same thing with a Guangxi, coticule, and translucent but I did just over 100 laps.

For me the translucent was head and shoulders above the other two in terms of keeness and smoothness and I liked the guangxi better than the coticule. Of course that was my razors, my stones, and my face. YMMV.