Yup. Take a rag and spray some engine degreaser on it, then start wiping. Works well and you never have to worry about killing electronics. After the degreaser, do the same with some engine dressing, or WD40 I guess, and it will shine like original. NEVER use Armorall on anything. It may clean well but it will chew through connectors and rubber gaskets/trim. It's just not worth it IMO.
As for my valve cover, I sanded and sprayed it black while doing a valve cover gasket job. It made a world of difference compared to the peeling cover.