I post this everytime this thread comes up.
You cannot "neutralize" potassium chloride. Calling corrosive ammo "corrosive" is a misnomer. All you can hope to do is mechanically remove as many of the KCl molecules as you can.
The absolute best method is lots and lots of
BOILING SOAPY WATER. Bar none.
The soap will help breakdown the crud in the bore so you can start to access KCl underneath it. I use Dawn, but any other similar dish type soap would work fine.
If you can show me a better solvent than water for KCl I would love to know. No 40 dollar a bottle miracle solvent will do a better job. I use boiling water because it dissolves s**t better than ice water. The more you use, the more you can dissolve then flush away with new water.
Hit it with a quick spray of WD-40 down the bore if you want, displace any water that didnt already evaporate. Run a patch maybe and you are done.
Windex isn't bad, but torrents of boiling water beat measly squirts of room temperature water every time for dissolving/flushing away the higher number of molecules.
Go to Home Depot/Crappy Tire/Store down the road and buy a funnel and some tubing. Make the device that has been illustrated here:
and be done with it.