Here's a video on the way I clean mine. What do you do that's similar or better? Also, I need to say up front that I know this can remove the coloring on nitride finishes. I personally don't care about that.
These products, like lemishine, have lemon (citric acid) in them. Depending on how much you use and/or how long you leave the brake to soak in the cleaner, it can discolor the metal finish.
That being said, I have never had that happen and the people that have, say it's just on the surface and can be buffed out using a cleaner like windex that neutralizes the acid.
For me personally, I'm not at all worried about a slight discoloration of my muzzle brake. It still functions perfectly.
I soak my hellfire in a cup of CLR. Turns the carbon to goo. I had one that was really bad tried a bunch of different stuff CLR worked like nothing I had ever seen before. Yes the pink is copper and any kind copper cleaner will take it off