My own special mix of Ed's Red.... equal parts of Dexron ATF, kerosene, mineral turpentine and prep-wash ( a solvent used to remove wax from auto-bodies before painting).
I add about an ounce of Mobil DTE light (machine oil) per gallon.
I swab the whole gun and let it soak for about a half hour.... then wipe the gun down with a clean soft cloth.
The mix will clean all manner of reside out and off blue, stainless or nickel plated gun without hurting the finish of the gun or grips.
It costs about $10 a gallon to make and works as good as any miracle gun solvent that I have been able to find in the last 25 years.
I have 109 handguns and all of 'em get the same treatment !