+1 On bristle pipe cleaners soaked in alcohol. I normally use the 90% isoproplyl as it evaporates a bit more thoroughly but 75% would work just fine. Run the pipe cleaners through until all internal goo is removed and your pipe cleaner comes out clean. After that run a dry one through a couple times to remove any excess and you'll be in good shape.

For the exterior of the bit mild abrasive is the key. Over the years I've had good luck with anything from figernail buffers to xtra fine steel wool to baking soda on a tooth brush. Once all the oxidation has been scrubbed off, I normally apply some rubbing compound and buff with a dry, soft cloth.