Oil dissolving liquid will not remove metal particles imbedded in the stone.
Sometimes, a simple squirt of WD 40 will clean up a stone. Lacquer thinner will break down the oil and won't hurt the stone. There are hundreds of ways to clean them-depending on how they are loaded. I even use an ultrasonic cleaner on them.
After a thorough cleaning, there still may be metal clogging the stone. If so abrasion is the safest way to remove it, and abrasion will flatten the stone.
Hydrochloric acid will eat metal particles out of stones, but it's a PITA to deal with.