I made a wire mesh shaker the size of an old 8"x12" cake pan and just shake all the dirt and loose debris off the brass. The cleaner it is, the more you'll get for it. If they see a lot of junk mixed with it, they discount what they pay, but as long as it's just all brass, there's no problem. Just don't leave any steel cases mixed with it, or they will discount for sure. They usually just run a magnet through the box to make sure.
I keep the primers separate, just to show them, and let them mis it together when they weigh it. That way, there's no question about what it is mixed in with the brass cases. And they always empty your containers into their containers to make sure there isn't something hidden in there that isn't brass.
The last batch I took to the recycler paid for my fuel to go to the SHOT Show in Las Vegas in February. Almost $300 of "free" money isn't a bad way to go.
The price of brass is going up constantly. China and India are gobbling up metals at a growing rate, as well as demands for brass for the war on terrorism, so the price is going to stay up for quite awhile. It appears that lead prices are finally stabilizing after going crazy for the last couple of years, but all the increased demands for metals is going to directly affect the price of ammunition and components. Primers just took a big jump in price, and prices for brass cases are also rising.
Don't throw any brass away, since it can all be recycled. After all, reloaders were recycling long before it became a fad...........
Hope this helps.
Fred