you can certainly add rubs to your brine - keep in mind that a brine works through the difference in concentration by osmosis. That said, you have to make a fairly concentrated brine to get flavor to pass that way, especially with the relatively short brining time for poultry. I often add a bit to the brine, but count on still applying some on the surface before cooking. My favorite approach is to make a compound butter with the rub and use that under the skin.
Dean --> :grin:
22" Weber OTS, Weber Smokey Joe, 18" WSM, Charbroil Gasser, Propane burner for Low Country Boils