You can ziptie the crank arm to the chain ring - voile! It turns backwards.
Oh, and yeah, you can clean and oil a chain, but not from what your description is. Clean with WD40 and a rag first, then very lightly oil with chain lube - my go-to is TriFlo, but there are others, wipe off excess. Do this when it gets dirty again. I always clean the derailleur idler gears as well, they seem to get caked with dirt compounded with chain lube.