If you do use soap and water, use hot water as it will dry better with the metal hot. A squirt of WD40 will also remove the water. That is what it was designed for. If you are worried about the WD40, then hit it with Gun Scrubber after the WD40 treatment. Then re-oil. Dont put WD40 over other oil. That can cause problems.

CLP is also supposed to displace water also, but I cant confirm that.

Back in the 70ties, I got the bright idea to shoot black powder loads in my 4 inch blued M29. It fired all 50 rounds without jamming up. I detailed stripped it and gave it a hot water and soap bath. Relubed with WD40 and had no rust problems.

I was also using the cap and ball revolvers in those days. Detail strip and wash with hot soapy water was standard for those.

Back around that time, I was buying WWI dated boxes of 45 ACP milsurp for $2.00 a box. I used the soap and water method for cleaning the cylinder and bore of my M1917. Relubed with WD40 and never had rust.