The BK2 ferrule should be a good grade of LBM.
The Maxlite & Titan ferrules used on the play shafts are the ones that don't like solvents.
If you're going to clean an LBM ferrule, it should be sealed when you're done.
Otherwise, the newly exposed linen fibers will quickly attract chalk
and your cleaning of the ferrule will have been for naught.
HTHs, KJ