I was given a nice old 10" cast iron skillet from the 1950's. Only problem is the former owner sprayed it with WD40 in his garage so she wouldn't rust. Any chance of bringing it back?
If you do a search, WD40 is a 'secret' formula. That it's made of fish oil is an old myth. Bottom line: it's a bunch of chemicals that are not designed for use with food. Heat it, scrub it, it doesn't matter, it's not for use with cookware.