FWIW,early in a gunsmith friend's enterprize,he soaked a S+W 29 nickel plated cylinder in Hoppe's #9.Took off the nickel.
Schueman barrels is one of the Cadillac 1911 barrel makers.If you go to their site,and explore "cleaning" you will find Mr Schueman's opinions on using chlorinated hydrocarbons such as TCE,present in brake cleaners,etc.
It has to do wioth 416 stainless,sulphur in the steel,and problems.
Not all "good ideas" are good ideas.
Boiling water was a fine idea.Some things are water soluble and not oil soluble.
Most of the suggestions (Kroil,solvent,kerosene,ATF,etc)are all commonly used and fine.