I would use lacquer thinner on a rag or paper towel and get as much of the sealer off as possible. Lacquer thinner will dissolve most resin type finishes. Once as much sealer has been removed as possible I would then use a Magic Erasure and ammonia to clean all the dirt and residue left on the shaft with the shaft not revolving. The Magic Erasure works much better when it is being rubbed with the grain, not cross grain. When shaft is clean and bare then you can spin in your lathe at around 1500 rpm and dry completely with a paper towel. Once the shaft is dry you can now bring back the smoothness by slight, judicial use of either 600 or 800 grit sand paper then go to 1000 or 1200 grit and then burnish shaft with leather and reuse your sealer and finish that off as usual. The only time I use any grit coarser than 600 grit is when I'm either building a new shaft or re-tapering one.
Dick