I have this nice old strop I got on ebay. Shell hide, very thick and very smooth, no nicks of any note, good linen. There was a rough patch near the top, and I decided to lather it up and give it a light scrub with a pumice stone - this seeming to be conventional wisdom on how to smooth a strop. The pumice just roughs it up! Now it's more like ultrasuede, instead of glassy like the rest of the strop. I've put rubbed strop conditioner into it, taken a rolling pin to it, etc., to no avail. Does anyone have advice?