The best way to get good with any coticule you have laying around, including one that doesn't seem like it will work that fine, is take a bevel set razor and ban yourself from using anything else other than the coticule for several months. I guarantee if you can hone with any other stone, you'll find out what the coticule likes and get an edge you can live with. Same goes for any stone that has a marginal reputation.

There's something that always occurs to me with that, though, and that's that even once you master a coticule you have, if you go back to your old favorite after that you'll probably think "I still get a better edge easier with ___" (for me that's a thuringian or a good japanese stone).

Marginal oilstones and coarse-ish coticules, I have always been able to get a good edge on the nth shave, even if I can't get a great one right off of the razor. Which goes back to the way some old literature describes an edge, where you coddle the bevel a little bit to keep it in shape, but never work the linen-prepared edge off of a razor. Those are the kind of things you stumble on if you force yourself to use a stone that otherwise feels like it provides an uncomfortable edge.