ORIGINAL: spaceworm
Another caveat. The AF mix in the crockpot will turn some ENYA crankcases and other cast parts dark gray (again, don't ask me how I know). This may be a function of how long you cook the parts, but, overnight overcooked my Enya. It was not damaged but the color was dark.
oven cleaner does too if you leave it on too long...now i still use it but spray it on, then scrub with toothbrush...then quickly spray it off with rubbing alcohol to get oven cleaner residue off....then repeat the same process a couple of times till the motor looks "like new" condition