Loosen the skin of chicken on the open sides, you'll notice it adheres strongly to one side in particular, let that side stay attached.
Square the chicken thigh with a boning knife, by laying it on its skin side down, the skin should now be pushed to side where it does not get trimmed away (make sure that the one side the skin is attached, stays attached!).
Now trim the knuckle off the bone, there will be a groove where your heavier chef knife will do the trick just inside the knuckle bone, press hard with the back end of the chefs knife, give it hard short hit to the knife end with your palm to get the knife through. Trim any pieces of cartilage you may have missed and in general any veins, tendons or any thick pieces of fat that will not render.
Trim the edge of the other side of the knuckle you removed, just square it off.

Wrap the skin around the whole thigh, tuck in ends, smooth the top and tuck tuck tuck. Place 8-10 thighs in each large zip lock bag and add 4 cups of the chicken stock to each bag.
Place the marinated thighs in the refrigerator for 5 hours.

Remove the thighs from the brine and place skin side down on a wire rack with a sheet pan underneath it.
Mix all the dry rub spices together. Sprinkle the dry rub spices evenly over the bottom of the chicken. Don't be shy because a lot of flavor needs to come from that single bite that judges will take!

Now it's time for the spice rub.

300°F. to 310°F.

Put the chick thighs skin side up, making sure they are wrapped snugly in their skin in an aluminum baking pan, 8 to a pan, use a whole stick of butter, cut into pieces, tucked into the sides of the chicken and pan and between the 2 rows of chicken, you don't want to put the butter on top of the chickens skin to keep the spices adhered.
Now a quick thin spritz of I can't believe it's not butter spray over the top of the chicken will help to break down any fat in the skin.

Place in an offset heat source BBQ for 1 hour.

If the color is looking good then put a temperature probe into one of the thickest thighs and wrap the top with tinfoil so you don't burn the chickens skin. You are looking for 196-197°F.
Once the temp is hit, you want to have a quick dunk in your BBQ sauce, let the thighs sit back on a wire rack so the excess sauce drips off and add it back to the smoker for 10 minutes to set the sauce.

The final step is to give the thighs a quick spritz (through a spray bottle) of apple juice to create a shiny sheen on top.
Use any chicken that is too small looking or the skin shrunk back too much as your taste tester, check for salt content and bam! time for the judges to judge!