I am not a chemist and I readily will defer to anyone who contributes to this forum who is one. That being said, it is my understanding from a number of sources, over the years, both personal contacts and online and in print, that water is not as good as water plus ammonia for dissolving and cleaning out corrosive salts that resulted from using corrosive ammo made post 1920s. Ammo made prior to that sometimes contained mercuric primers - also corrosive but very different (if you have anything with mercuric primers you very well may want to check into getting rid of it safely and not sooting it).
For the corrosive stuff made post 1920s, the addition of enough ammonia to the water, along with the addition of a bit of dish washing detergent, I have heard it told that said solution will actually neutralize the corrosive salts, dissolve them and wash them away. While many people use Windex, at least one online source and a couple of personal contacts have recommended using about 15% to 25% household ammonia (by volume) mixed with water to do the job properly. (Note most household ammonia products are about 5 to 10% ammonia in water, although 10% is commonly called janitor strength.) One of the properties of ammonia, for which it is best known, is its ability to dissolve many types of salts and to ionize them. I am not certain if it is effective on the type of salts left behind by corrosive primers but someone at sometime must have certainly thought so because ammonia is now included in gun cleaning products not only as a copper solvent but in order to remove corrosive salts and ammonia had been used for that purpose for years before that.
One of the best things you can do, when shooting corrosive ammunition, is to clean the barrel (and if applicable, the gas port and tube) very soon after shooting. If you do use anything with ammonia you may want to avoid using a phosphor-bronze cleaning brush until you have thoroughly cleaned the ammonia out of the barrel. As I recall, ammonia is a copper solvent and bronze is a copper alloy.
Remember that when using Ammonia products you want to be very careful not to get it into your eyes, not to ingest any and to pretty much avoid prolonged skin contact. Safety goggles are a good precaution as would be protective gloves.
Of course, you can play it safer for your health and use soapy water to clean the firearm parts effected by the salts. That has worked for me as good as the ammonia seems to have worked.
All the best,
Glenn B
whoa is me, whoa is me