Do you do washes or powders? (I just use craft acrylics and thier dirty brush water for grimey weather washes. Blk/brwn/grn but with pigment specs of "every color on earth" or in it, or around it, swish the water around and start pouring, lol. ( I actually mop brush it some to fill corner and edge detail well, then pour. It can take a few dumps so I recover it in a glass pan sometimes)
I'm wondering if one of the model paint companies offers a small bottle of etch primer? And they do make quarts you could brush from but its kinda rare to see it on shelves really. And owch... how do I get a splinter in the top of my foot while sleeping? 
I gotta go...
