Muc-Off Chain & Gear Degreaser Muc-Off Chain & Gear Degreaser is safe to use on metal, plastic, rubber and seals, and is fully biodegradable - after you've applied it you can simply rinse it away with water. Over time, the grease you put on your drivetrain begins to attract dirt and debris from the road or track. It turns into a thick, black, grimy substance that makes changing gear less efficient and can degrade the components. Every now and again, you need to get rid of it. Ordinarily, that would be an extremely messy, time-consuming job. But not with Muc-Off Chain & Gear Degreaser. This essential bike care solution eliminates built-up oil, grease and grime in a matter of minutes, leaving your bike parts completely clean and ready for a fresh new coating of oil.