1. Rinse fish.
2. Combine 1 gal. water and next 4 ingredients in a large bowl, stirring until salt dissolves. Add mullet; cover and chill 45 minutes to 2 hours or to desired degree of saltiness. (Cut off a small piece of fish, and fry it to determine degree of saltiness by tasting. Longer soak times yield saltier fish.)
3. Rinse fish, discarding brine mixture; pat fish dry with paper towels. Place fish on wire racks in roasting pans; cover with paper towels, and chill 2 to 3 hours or until dry. Rub 1 tsp. pepper on both sides of each fish.
4. Soak wood chips in water at least 30 minutes.
5. Prepare charcoal fire in smoker; let burn 15 to 20 minutes.
6. Drain chips, and place on coals. Place water pan in smoker; add water to depth of fill line.
7. Place fish on upper and lower food racks; cover with smoker lid. (If smoking fillets, place skin sides down on racks.)
8. Cook 2 hours or just until fish flakes easily with a fork. Garnish, if desired. Serve with saltines, hot sauce, and lemon wedges, if desired.