i took the whole thing apart, as far as the bare wood stock.. laid each piece on at a time on a folded towel on the floor and shot the living hell out of it, like a push broom only heavy pressurized steam from the jet nozzle. you can see the cosmoline turn into an emulsification and foam off...
each piece will dry in a minute as it is hot.
set aside.
hold the barrel near vertical (i stood it up at a 45 degree angle) and fire into it, rotating the barrel to ensure the pressure gets equally applied.
a nicer unit will do it in one shot but my toy sized steamer didnt get everything, but it sure heated up the barrel!! and loosened the gunk and sweated the cosmo.
all i did was fill the barrel with WIPEOUT (use whatever cleaner you like but that one is an expanding foam that eats anything and leaves a corrosion inhibitor dry finish that eliminates the need for extra oil) then three patches and the barrel is mirror finish.
I used the original cleaning rod and just shoved a couple .50 calibre patches thru.. but it just loves doubled over .30 calibre patches too.
all the little nooks and crannies in the receiver area, the rails for the bolt and cover, the trigger seat, all of it cleans out with steam no problem, its like a jet wash. then just wipe after and give it a drop of oil.
Its good to follow the steaming of the barrel with a hit of solvent then an oil or corrosion product just to make sure everything moisture related is out.. but its so hot you have to hold the barrel with a towel so no worries about drying!