Its name is actually CVA BARREL BLASTER WONDER GEL SOLVENT, and the CVA product label also says that it's a "concentrated gun cleaning gel" and that it "removes rust without harming barrel finish".
I've heard that it works especially well to clean up gun barrels that have been neglected. When a gun barrel is encrusted and looks like it should be thrown out, that product can do a tremendous job cleaning it up to look almost like new.

Close up photo:

http://www.natchezss.com/images/products/CVAC1684.jpg

Here's some user reviews from Cabela's:

http://reviews.cabelas.com/8815/2158...ws/reviews.htm