My experience with 4 year old Tri-flow is that any build up powders off like the finish on a teflon skillet then things turn very nicely. You are not using a huge amount of it. It does work very quickly. I can see that the transmission fluid might be nice when you have a more stuck than normal situation. I did buy a couple cans of Kroil but haven't had time to mess with it. If what ever your free it up solution could damage paint, use caution and adequate protection for the paint. I do know that Wilbur believes in Tri-Flow. We had two or 3 old stuck machines out back last summer. I gave Wilbur a bottle of clear sewing machine oil because being 4 he tends to go hog wild with the oil for the machine he was oiling. Then I gave Lovie Tri-flow for her stuck machine. We oiled and pulled out threads. All of a sudden Lovie's machine moved. Wilbur looked over there then looked at his machine and his oil. Then he said, "Grandma my machine needs that brown oil, too." You can't fool a little kid.