One thing I've learned wrenching, a 50:50 mix acetone and ATF mix, shake it well and soak her down, works great on stuck crap, even better when you can warm the area and knock/beat/bang it. I've worked on some nasty stuff, maggot mashers, honey wagons, gut wagons, trash trucks, stuff most people would blow groceries even smelling. Tried PB, Kroil, WD40(seriously
, water works better), engine oil, gear oil, refrigerant oil, machine oil, air tool oil, diesel fuel, kerosene and tons of other spray lubes, I always go back to acetone and ATF.