I know this is kind of involved but it turns out great all the time:
Put the fillets in a mixture of 1/4 cup kosher salt and a gallon of water let sit for about 15-20 minutes. Remove them and rinse in cold water. Dry them with paper towels as good as you can. You can use the same rub recipe, or anything that is about half salt and half brown sugar. Sprinkle a generous amount on each fillet and then put the fillets together flesh side to flesh side so the skin is on the outside on both fillets. Wrap that tightly in several layers of plastic wrap so it is air tight. Put it in a cake pan or something similar and weight it down with a heavy pot or something and place in the fridge. After an hour, flip it over on the other skin side and replace the heavy pot and put them in the fridge for another hour. After 2 hours total, remove the fillets and rinse all the rub off and again, dry very well. Now is the weird part. Do this in the basement where it is cool. Place the fillets on an oven rack flesh side up so they are separated and place them somewhere with a fan blowing on them for at least 2 hours or until the flesh side becomes almost dry and leathery (that's called a pellicle). After the pellicle has formed, place them in a 150-155 degree smoker until the meat reaches 152. That should only take a few hours. Make sure the smoker never gets too hot because the fish will cook. You will need to refrigerate this afterwards. It turns out excellent.
Rub Ingredients
1/4 cup pickling salt
1/4 cup seasoning salt
1/2 cup sugar (white or brown)
1 Tb Chili powder
1 Tsp black pepper
1/2 tsp garlic powder
