For what it is worth
Got some Makarov double into single stack 10 round magazines. They arrived complete with good Russian cosmoline. It has been so long since I have cleaned off cosmoline I had to look up how to do it. Metal should be easier than wood, so I was leaning toward Goobegone. At the paint store I ran into a product called Crud Cutter. Took the mags apart, and put them in a tray, sprayed them down, covered with soaked paper towel and let them soak over night while I drank to the liberation of Cuba. Today I sprayed again and scrubbed with a brush and rinsed with water. Two springs, two floor plates, plastic follower, and plastic connector between the springs all came out perfectly. A little CorrosionX on the springs and they look beautiful. Good stuff I am thinking. Simple Green would likely have done the job too.