I have used Unique's sealer for a long time and it is a very good product.
dries fast and a few coats seem to seal nicely.
I am thinking that if you mix your own it would be OK also.
50% thinner and 50% lacquer might do it.
What you are trying to do is seal the open wood grain to keep chalk dust and other dirt from getting there where it is ugly and hard to clean out.
It also works as a sanding sealer allowing you to get a very smooth surface on the shaft.
Other wood sealing products like General Finish Endro Sanding Sealer can do this also but what you want is one that dries fast. Endro takes about 10 min between thin coats on a shaft while Lacquer dries in about 2.
Willee