Just received a free Delta chuck from when I purchased the new Delta Midi lathe. It is a Nova G3d chuck, (G3 made for Delta), and it was in a plastic bag with that heavy protectant all over it . It did, however, just wipe off with a rag, (didn't sling all over when I used it on the lathe after cleaning either.) Took a little time to get it all out of the grooves and teeth, but is now nice and clean.
If I had to use a solvent, I'd vote for the mineral spirits as well. The protectant seems to be petroleum base and the MS should cut it.