I always carry a spray bottle of ZEP glass cleaner mix and a roll of white paper towels. I mix the ZEP myself from concentrate and like to make it a little strong, so it will remove oils like that MC gook and oxide, but not so strong that it takes latex paint off walls.
I use it for cleaning just about everything. Every light fixture and wall plate gets cleaned after installation when I do the finish on a new house.
Watch out for those paper towels with the color prints on them though. That print color stuff [Soy ink??] comes of on the walls and leaves a nasty stain that is extremely difficult to remove.
