Rarther than tying the head in a dubbing loop, Spin the material as if it were deer hair and then trim to shape with a razor blade. You need to use material that will absorb water to aid in getting the fly down. Wool or opposum rather than dear hair. Although you may want to spin one or two clumps of hair for the fins.(I would use feathers instead) Spinning works best on a bare hook shank. And by spinning, you can varie the color with each spin to achieve that mottled look of a sculpin.
Hmmm,,,,wonder if there are any sculpin in the Rogue?
I fish because the voices in my head tell me to