I am using some naval jelly to remove light rust from several cast iron tool tops. I start by brushing a light coat of jelly on the top, let it sit for 5-10 min, scrub with a scotch brite, wipe with a dry rag, and then wipe with a wet rag (instructions say to rinse with fresh water). After wiping with the dry rag the top looks pretty good, but immediately after wiping with the wet rag green splotches appear on the surface that have to be sanded out. It’s clear that the wet rag is messing up the finish. However, I’m afraid that if I don’t use the wet rag some residual jelly will remain and keep etching the surface. Any thoughts on where I’m going wrong? Thanks