The wood itself will polish up nice & smooth. A good wax over the bare wood will enhance the smooth feel and give some longevity. I don't use sealer on my shafts, finished or between cuts. Oddly enough, I like for them to breathe. Warpers will warp regardless, and stable ones will always be stable. If there's a grey area in between that will stay straight only if you seal them, then I wouldn't use them in the first place. Nothing against sealing, as sealing a stable shaft won't hurt it. Some guys feel they can get a smoother or longer lasting smooth by using sealer, and that's fine. I'm not convinced. Everybody does what they do for their own reasons. I'm not posting this to argue with anybody or knock a technique, just offering another point of view. Heck, I have used everything from dielectric silicone gel, Kiwi boot water proof wax, shellac, oil & water based sanding sealer, etc. to seal shafts over the years and they all did just fine. Turns out that not sealing at all works just fine, too.