It is worse on blued guns than stainless. We used it for a couple years until we left it in some blued guns. Parkerized guns are really affected. We just don't leave many guns blued and 99% leave here with stainless barrels. Most blued actions we work on end up Cerakoted and nothing touches Cerakote. Here is a couple examples on Park and bluing. The first is a brand new parkerized Remington MLR. I chased brown patches for a week soaking overnight each time till we noticed this.
According to the can it said to store it with a light coat in the bore so once clean I put in the Accelerator and WipeOut foam. Then pushed a couple dry patches through. No oil.
Looked good going in.
Opened the bolt a couple weeks later to this.
One of our customers who we had built 7 rifles for him at that time called telling me his Bat action was all rusty. He had stored that one with WipeOut according to the instructions. Once we polished off the rust his bolt still shows pits on it. A few of his other rifles were damaged by it the same way. I contacted WipeOut, showed them the pictures and relayed all the stories and though it is easily recreated they continue to deny that this is possible. I returned what we had and they replaced it. The new stuff still did it. A few months later I was showing it to someone here in the shop and it was coming out of the can rusty. It was eating the can. Again WipeOut denied it. I can go on and on about WipeOut.
At the advice of Kirby Allen we switched to Bore Tech Eliminator products. No problems since. You can even cork the barrel and fill up and soak for a week with no troubles.