I've lightly turned it off the bushing with a parting tool. Paste wax on the bushings before finishing works, but use it sparingly. I've also finished between centers, without bushings. It works but is risky, you put too much pressure on and you expand the tubes.
I've heard a lot of good about the products Mack mentions above. I haven't invested in any because I haven't been making a lot of pens lately, but, if I get back to it I will.