Rinse and pat the catfish fillets dry with paper towels then place them in a large mixing bowl. Whisk together the buttermilk, hot sauce, and salt in a separate bowl and pour the mixture over the catfish. Soak the catfish covered in the refrigerator for at least 1 hour up to overnight.

Meanwhile, in a large shallow dish such as a pie plate or baking dish, whisk together the cornmeal, flour, paprika, salt, garlic powder, onion powder, celery salt, cayenne pepper, and black pepper. Line a baking sheet with a wire cooling rack and set aside.

Working with one piece of catfish at a time, remove each piece from the buttermilk and allow the excess to drain by holding it over the bowl with your hand for several seconds. Place the catfish in the dish with the cornmeal breading. Flip the fish over to coat both sides in breading, gently shake off the excess, and transfer it to the lined baking sheet. Allow the catfish to rest on the baking sheet while you heat the oil.

Pour enough oil into a 7-quart Dutch oven to go 3-inches up the side. Heat the oil over medium-high heat until it reaches 350°F then lower the heat to medium to maintain the temperature.

Carefully drop two pieces of fish into the hot oil and cook for 2 to 3 minutes on one side. Carefully flip the fish with tongs and cook for an additional 2 to 3 minutes until crispy and golden brown. Use a slotted spoon or spider strainer to transfer the catfish to a paper towel-lined plate to drain. Allow the fish to cool for about 5 minutes and enjoy!