In a mixing bowl, stir together cornmeal, cayenne pepper, paprika and onion powder. Mix well. Pour mixture onto a large sheet of waxed paper.
Heat oil in a large skillet over medium heat.
Pour milk into a medium bowl. Dip catfish filets into milk and hold up and let the milk drip off. Roll the milk-soaked filet in the cornmeal mixture until completely covered. Set aside.
Fry the garlic in the hot skillet, but do not burn. Add the coated catfish filets and cook for 5 to 7 minutes on each side, sprinkling salt on the fish after each turn. Cook until golden brown and fish flakes easily with a fork. Drain on paper towels.