I use a dry brine similar to you... brown sugar, kosher salt and various other spices. I rinse my fish and pat it dry with paper towels. Then put it immediately in the smoker and plug the smoker in. I dont bother with the air dry thing. If you look in the smoker after 45 minutes or so you fish will start to look like its been air dried...

One of the best tips I can give for smoking fish is to slice the fish into 1" squares. I'm not talking about all the way thru the skin but close. Then, I hold the fillets so that the slices open up and I sprinkle the brine into them. The brine soaks deeper in to the fish and the smoke is more thorough.

Plus when it is finished it will be in bite size pieces...

I rotate the racks a couple of time while smoking so they even out. the bottom is definately hotter than the top...