The feedback I saw was from hardcore bullet casters (they spell it "boolits" if you're searching). This was 12 years ago. The product got some extremely negative feedback from them and was alleged to make leading *worse*. However, the same guys said it significantly reduced powder fouling.
I won't catalogue the methods these guys use to drive cast lead, sometimes at modern velocities, without lining their bores with smeared lead. But they are technologically innovative, have an extensive repertoire, and the product in question isn't included from what I see.
Patched balls don't lead barrels. Maybe the product would make powder fouling easier to clean. The manufacturer said, if desired, the product coating can be removed from a barrel by using brake cleaner.