Smallpatch, I do lightly sand with very fine sandpaper between coats, then vacuum the stock, then a light rubdown with a barely damp cloth. I do this between every coat. I don't use steel wool at this stage. After the final coat has dried I have lightly sanded it using very fine steel wool to knock back the shine a little. Chambers finish is very easy to use and forgiving. I have finished a stock by hand rubbing each coat. I have also applied the finish with a piece of clean hard cloth, then sanded, then the last coat is rubbed in by my palm. Both methods worked equally well.
I do know about filling the pores in walnut by using sandpaper and oil to create a slurry which fills the pores but I wasn't thinking about that in my earlier reply. I was only thinking about the maple we use for gunstocks. I have never seen the need to do this with curly maple.
This my .40 caliber Turkey rifle. It has 8 hand rubbed coats of Chambers finish which produced a hard, deep shine. I used fine steel wool to knock back most of the shine to help prevent reflection and in general make it harder for a turkey to see.
The rifle and finish have gone through over 15 seasons now and the finish has held up well through rain and shine.