https://www.youtube.com/watch?v=-DkqTz8a_PU
I followed this guide and it worked fine with me. If you don't put a clear coat over it, it'll get beat up and look badass in just a few weeks. Then you can clear coat it to keep that look longer. IMO, a beat up paint job shows a lot more "character" to a gun.
TL;DR, Krylon Camo isn't crap, it just allows you to get the beat up look a lot easier.