I went to the range and shot what I had to.
A long time ago I read AND heard that windex with vinegar is great for cleaning bp.
I didn't have any so I mixed water and some vinegar in a spray bottle. I used maybe 3-3.5 oz of water and 1-1.5 oz of vinegar.
There I am cleaning away and lo and behold, it removed the blue off of the muzzle.
What an eye opener.