Help

so the other night we were all baked out of our minds and decided to bake brownies. needless to say the vegetable oil caught on fire, but luckily i was able to put out the fire by way of fire extinguisher. however, some of the fire extinguisher residue got on the marijuana that we were going to put in the brownies. does anyone have any tips or info on how to clean the marijuana, or is it completely wasted? i hope not. the residue is a powder, and there's not a lot of it, so is it possible to blow dry it off or some other way? please help, and thank you for your comments