For what it's worth, I hot blued guns for many years, and used some nice stainless baskets for holding small parts. Occasionally there would be one or two parts in the basket that came out white, no blue at all. I would take them out , swish in Brownells rust remover diluted, back in and they would blue fine. After switching to black iron screen baskets, the problem went away. I was using Brownell's salts.
It is not a very scientific test, but the results seem to indicate something.
Lets hear other reports.
