Have you tried 0000 steel wool for between coat sanding or the de-whisker?
I have before but prefer 600 grit paper. I've found steel wool will sometimes deposit particles in the wood that don't come out until the finish is applied.
Also, after the finish is applied you want to be VERY CAREFUL about rubbing or sanding it with anything. after the sealing coats are applied if you "break" the finish you might as well start over again. Even if the area is "patched" where the finish was broken/rubbed through it will always be noticable and simply isn't repairable even with multiple coats.
