Thanks everyone. I like Ray1970's work there, you're right, it is functional, but less traditional. I pretty much took the lazy way - a couple of cans, a mesh bag, or in the Ruger PC Carbine, a bunch of dead twigs I scooped up in the backyard.

So far the finish seems fine, but it varies based on the surface. On my full stock AR, the Magpul MOE handguard and the A2 buttstock have a bit of a rougher texture, though I also haven't shot it much since I painted it (that'll change soon!). On the metal handguards of my Ruger PR and Noveske upper, it feels perfectly smooth.

I haven't noticed any flaking or powder, and I've shot the brown and khaki AR a ton. The most wear seems to be on the buttstock where the cheek contacts, and the pistol grip. As it fades, I may try an urban gray pattern, just because.