For years I and probably half the Free World used a mixture of motor oil and mineral spirits as a general gunscrubber. My stuff maybe went something like 3 parts motor oil to 3 parts mineral spirits. I wasn't too technically attentive of the exact mixture of the stuff because it worked well in seemingly wide variations of mixtures. Sometimes I added other stuff that looked promising and sometimes was.

Then I read of CE Ed Harris' "Ed's Red" which is the above plus Dextron II or III and Kerosene {mazut or paraffin to you Anglo/French fellows} in a specific mixture. The acetone is dissolved by the kerosene and then that solution dissolves in the transmission fluid. Or vice versa, the techies to elaborate, I'm sure {hope}.

Anyhow, Ed's Red is a solution, the mere mix of trans fluid and acetone is not. I just mixed some Dextron III and acetone and indeed it separates. So does motor oil and acetone. But the big jug of Ed's Red stands as a solution on my gun bench.

A very thin mix of solvent {mineral spirits} plus motor oil {latter doesn't seem to matter too much exactly what} does indeed make a very good penetrating oil. Kerosene and acetone or Kerosene and mineral spirits will often break a rusty nut, too.