If this gun is one that you intend on shooting often, I would just use a toothbrush with your favorite solvent and call it a day. That procedure will still leave the markings on the cylinder face, but you will have reduced any accumulation that would cause binding.
If this is a Safe Queen and you are going to drool on it instead of shooting it, you can use a pencil eraser. Yes, a standard #2 yellow pencil eraser will work. A bit more aggressive and faster is the ink type (white ones) if you have one. This procedure should not be repeated often as even though they look harmless, pencil erasers are abrasive. Another good alternative is a Lead-A-Way wiping cloth - again, do not use often on Nickel or Blue.
Just one of the reasons I like Blue guns is that the cylinder face markings don't show as badly if you clean them with solvent each time they are shot. Stainless can obviously take a bit more cleaning without sustaining damage.
Suggestion:
A clean gun is a nice gun, but don't clean it to death.
Chief38