Crox is nice, either on a paddle strop or your canvas/linen hanging strop. I prefer the paddles and like to keep my hanging strops virgin. I have SRD's hard wool felt with .50 diamond spray, It's great too, I find Crox to be smoother, less irritating than the diamond. I really can't even use .25 due to irritation. SRD's .50 spray on the wool felt is really nice too...It'd be hard to pick one.