I'm not sure about the corned brisket but on the hens you have to be careful when using a brine that your rub doesn't have a lot of salt in it. A friend of mine cooked some chicken that he brined and his rub had too much salt and it was uneatable. I remember recently some one posted about cooking a corned brisket but I can't remember who it was. Good luck on the cook!
Also keep in mind a lot of poultry is injected with a salt brine to increase package weight. I never add any salt to my poultry if it is already injected. If not, I do a very light dry-brine with kosher salt overnight. Either way, my rub always goes on an hour before it hits the smoker and none of my rubs contain salt.
I'll make sure to use a rub with no salt on the birds......I have to make the pastrami rub again.....I asked the wife to change out the water I was using to desalinate the brisket and she did change the water...only after adding in my rub I made for tomorrow...oooops. I re-rinsed it and will rub it in the morning for it's two days in the fridge all rubbed up.