Ok this is off the wall but i tried this for the first time today on the nuts that hold on the egr pipe to the exhaust manifold that had been on there for the last 10 years and were pretty rusty.

I had read about this elsewhere on the web, basically mix 50/50 ATF and 100% pure acetone together, it needs a good shake to mix it properly, i brushed some of this onto the nuts, the manifold was still warm so i could see the acetone in the solution fizzing a bit. after 3 applications i then undid the nuts they came off with a crack but all the way down the threads of the stud you could see the solution, i am amazed.

ian