I learned about Blue Wonder gun cleaner June 2011 at NRA Basic Rifle at the Durham Rifle and Pistol Club. The instructor's name was William Guyer. Guyer explained a lot of gun lubes and gun cleaners are toxic and cause cancer. Guyer gave the class a list of his personal favorite gun cleaners that are less toxic and bio friendly. One was Blue Wonder. I finally bought some this year to clean up two older shotguns, including a 1936 Winchester Model 12 shotgun I am rebuilding at the Gunsmithing program at Montgomery Community College in Troy, NC. I have found Blue Wonder more pleasant than my standard Hoppes #9. Blue Wonder take rust out better than Hoppes #9 and does not have a "causes cancer in the state of California" warning label on it. Guyer told us to look for that label when choosing a gun cleaning or lubricant product. It also smells better than other bore solvents and it removes plastic shotgun was well.
I used half of bottle blacken my barrel over and over never got black dark