I use a mixture of 1 oz hydrogen peroxide, 1 oz dish soap and 1 oz water soluble cutting oil from Napco in a quart of water. Learned about it from a local BP gunsmith who is a record holder. Also works as a patch lube for the range. It will protect the bore but for the outside of the gun use a gun oil. It was designed by a chemical engineer. The soap and water remove the salts and the oil and peroxide penetrate the pores of the bore.