This is half the recipe for Ed's Red Bore Cleaner that also has paraffin and Varsol
(which is an Exxon-Mobil trade mark) in equal parts (1/4 each), inexpensive and works better than commercial products.
You could try soaking in the complete formula.
Found this when searching for Varsol:
"Odorless mineral spirits, Stoddard Solvent, white spirits, Varsol - all pretty similar. Try Klean-strip odorless mineral
spirits - $10.50/gal at Home Depot. Cheaper paint thinner would probably work just as well."
Rockdoc's idea of using the drill press works great.
JC
