HarleyBob,
What keeps the mohair from sticking out and being 'hairy' is traping the fibers under the successive wraps.
You can try a couple of things.
First, as you wrap, stroke the fibers back towards the hook bend with your fingers after each wrap (asssuming you are wrapping FORWARD from the bend to the hook eye). This will keep more fibers from being 'trapped' under the wraps.
Aftr wrapping, instead of a tooth brush, try stroking the fly with the hook side of some velcro. This will 'grab' the fibers and 'pull' them from under the wraps. Do this from front to back. You can also pick the fibers loose with a dubbing needle or bodkin, but that takes quite a bit of time.
Good Luck!
Buddy
It Just Doesn't Matter....