Gun Scrubber got a major reformulation a few years ago to elliminate the CFCs from it. They totally changed the product, but the package stayed the same, they didn't even put "New and Improved" or anything.
Benchmade used to recommend it for their folders and I used it. Then, one day, I got a new can and tried to clean out one of my AFCKs and the stuff attacked the spacer. I called BM and they confirmed that the new formula Gun Scrubber is much more agressive and will attack plastics and other finishes. They no longer recommend it.
I've heard of it taking the paint right off of sites. Gun scrubber is fine on metal, but watch it on plastics and other materials. And a lot of guns today have some non-metalic parts, so be careful with that stuff.
Some time ago, a friend was all excited about this new gun cleaner he had found. He said it smelled really strong but really cleaned well. I took one whif and knew what the active ingredient was: ammonia. It just about knocked me backwards. At one of the ranges where I occationally shoot, there's a big pump bottle of some blue liquid soap in the bathroom. The sign cautions to use just a small amount. The stuff works great. It takes the residue right off of your hands. So, I asked what it was. The answer: Dawn Dishwashing Soap. The key ingredient in Dawn Dishwashing Soap that makes it the only dishwashing soap powerful enough for bachelor cooking is actually ammonia. So, I got to thinking? Why not Windex. It's cheap, you've already got a bottle of it around the house, it doesn't smell bad, it doesn't leave your hands smelly, and it's got plenty of ammonia in it. So I tried it and it works great. Why pay for all of these expensive potions when ordinary Windex does the trick.
Follow up with Militec-1, and you're done.