It`s been used to clean the final drives on shaft driven motorcycle with great results. It`s ingredients are mainly petroleum and cleaning products. Both of what you want when you clean a chain and or gears.
Last week I oiled my chain. Then wiped off the excess. Then I poured some Marvel Mystery Oil on a clean rag and ran the chain through it. The chain came out noticeably cleaner and shinier, and the rag was very dirty.
The chain was pretty clean before and after I oiled and wiped off the excess, but was even cleaner after wiping it with the Marvel Mystery Oil soaked rag.