This is just a rundown on the reasons for cleaning your your barrel/lock/barrel extension and feedblock with hot water and soap.
First - the reason corrosive ammo corrodes is due  to the deposition of strong oxidants in the barrel (Chlorates, usually) .  These oxidants are inorganic salts, and in the presence of water will undergo a redox reaction with the steel of your barrel (without water both the steel and salts  just sit there, dormant - as is demonstrated by leaving a 1919 barrel with 1400 rds of Turk 8mm uncleaned in AZ, no water, 3 months later, no rust).
    How many remember their 101 chem, or organic chem class?? There is a term that is invaluable when running experiments in these classes "LIKE DISSOLVES LIKE."  Inorganic salts are extremely POLAR (there are large + and - "ends" of the molecule) - water is also extremely POLAR (two positive hydrogens on one side, a big ol' oxygen on the other, with extra electrons, creating a negative side).  Oils and solvents such as hexane/toluene are NON POLAR.  They are usually a string of carbons with hydrogens spaced symmetrically around them (ie no unbalanced charge around any point).  These non polar solvents cannot dissolve polar salts, and are not miscible in polar solvents (ie, if you already have water and salts in your barrel, washing them with non polar solvents will not remove either water nor salt).
         I, being a chemist, and a gun nut, have done a bunch of reading on this stuff, I wanted to make a "Corrosive ammo cleaner" and looked up the solubility constants of these common oxidizing salts in various solvents.  Guess what?  None even come close to that of HOT WATER.  There is absolutely no comparison between hot water and any other solvent.  Add some soap to the hot water to cut through the grease (to help miscibility of oil and grease in water... want some background on micells?) - allow to dry, toss in the wife's oven (or buy a surplus oven and leave it in your garage, as I do... for moly coating, drying guns etc etc).  Then clean the gun in exactly the same way you usually have (hoppes etc).