Here is what I do to avoid the slurry dulling affect of a coti: BBW. Yes, you heard that right. After setting a cutting edge (aka bevel) on the coti, I do most of the sharpening on the BBW, since it's slurry doesn't have the dulling effect of the coticule, then I slowly delute to a milky consistency and hone away till I achieve a nice undercut. After that, i then move to the coticule with plain water. I've only honed on coticules and BBW's I've never honed on anything else and for me, they have been pretty straight forward and easy to learn on as they don't require a stroke count, just learning the stone and an undercut.