Place catfish fillets in a single layer in a shallow dish; cover with milk. Cover and chill 1 hour.
Combine cornmeal and next 4 ingredients in a shallow dish.
Remove catfish fillets from refrigerator, and let stand at room temperature 10 minutes. Remove from milk, allowing excess to drip off. Sprinkle evenly with 1 teaspoon salt.
Dredge catfish fillets in cornmeal mixture, shaking off excess.
Pour oil to depth of 1 1/2 inches into a large skillet; heat to 350°. Fry fillets, in batches, about 3 to 4 minutes on each side or until golden brown. Drain on wire racks over paper towels.