OK, it's pretty obvious that you have absolutely no clue about the history of corrosive priming and the pervasive issues, including that cropped up in the 1920s.
Investigation into those problems revealed the issues with corrosive priming, the cleaning regimes of the day, and the fact that in order to prevent rusting, a change in how cleaning was done AND a change in the bore cleaners was needed, which included adding either ammonia to the cleaning solution or, later, other types of surfecants.
I guess, though, what you're saying, is that you're so much more "larned" then those dumb military hicks from days gone by. Obviously you have some sort of "new science" knowledge that tells you that water is an effective solvent for gun oils.
You must have discovered some new and previously unknown type of water, so I'd suggest that you run out and patent it lickety split and market it as the newest cleaning solution.
Either that or somehow the laws of chemistry are different where you are.
IF water "worked fine," military and civilan organizations around the world wouldn't have spent years developing, fielding, and marketing specialized cleaning solutions to combat the known problems caused by corrosive priming residue.