Just had a look for it but can't find- a few months ago, I think it was Olev posted suggesting a 50/50 mix of acetone and ATF, to which I keep meaning to add my mixed (....the odds be 50/50) results . Try that and see, but stock up on cold drinks cos it takes a while. ..I have a 2" pipe cutter that had a seized citing wheel.
I'd tried all the obvious things to no avail, but as soon as I read the post I did it, and after a few weeks, the wheel was free. .. trouble is the acetone evaporates fairly quickly when the air is warm, and as someone else noted the two don't mix readily- may depend on the brand of ATF...! That's about the best I can do.