I think any penetrant "works" better if it's applied and subject to 1 or more heat cycles.
I learned about kroil when I worked in an auto shop where we installed a lot of tube headers. Spray some kroil on run vehicle for 10 minutes, spray a little more on let cool and remove the flange bolts and heat riser without ever breaking studs. Sometimes the stud would come out with the nut.
Is the mopar stuff called MP50? I've had good results with that, and pb too, but I don't like the smell of pb either.