I have a few because I tried a few lol! What I use depends on the machine, the paint, the age the clear coat and what I feel comfortable with. I ALWAYS test a hidden spot first and there are some I don't dare use anything but sewing machine oil.
What a product will or wont do totally depends on the condition of the machine. I think many people think that every vintage machine can be shined up like new. That is not the reality.