Simple is enough...
Just clean the residue from the bore and chamber by whatever method works. No need to 'neutralize' the primer salts, you just want to remove them along with the powder residue from the bore and chamber. After cleaning, lightly oil the bore, chamber and metal surfaces. Steel will naturally rust over time even without primer salts. The primer salt residue only speeds up the natural process of rust.
Just clean the residue from the bore and chamber by whatever method works. No need to 'neutralize' the primer salts, you just want to remove them along with the powder residue from the bore and chamber. After cleaning, lightly oil the bore, chamber and metal surfaces. Steel will naturally rust over time even without primer salts. The primer salt residue only speeds up the natural process of rust.