On metal parts, the kerosene is O.K. I wouldn't recommend it on plastics though. Although I've never tried it, I just won't take a chance personally. I've found that kerosene along with a slightly over-sized toothbrush is the best for cleaning the chain. I've also used kerosene on a cloth to get rid of road grime, tar, and any lube that may sling from the chain. Cuts through that stuff like magic.