Well, I like a mix of soy sauce and Italian dressing- but only for marinade.
For cleaning, plain old Hoppes' #9. If you are trying to deal with accumulated carbon and crud, low odor mineral spirits can also be used.
One of the best products I have ever used is KROIL. Made by Kano labs, it is (IMHO) the best penetrating oil made. Will get under carbon, lead or copper, and loosen it from base metal.