Classic Buttermilk Fried Chicken

Whisk together 5 teaspoons salt and 1/2 cup water in a bowl until dissolved. Whisk in buttermilk, eggs, onion, garlic, and 1 teaspoon pepper. Add chicken, and turn to coat. Cover and refrigerate, turning occasionally, 8 hours or up to overnight. Drain chicken and discard buttermilk mixture. Whisk together flour and 3 teaspoons salt in a bowl. Toss chicken in flour mixture, one piece at a time, until evenly coated. Return all of the chicken to the flour mixture, gently toss, and let stand 15 minutes. Toss again to make sure each piece is evenly coated. Remove, shaking off excess. Preheat oven to 325 degrees F. Line a large rimmed baking sheet with an oven-safe wire rack. Heat 1 1/2 inches oil and bacon drippings (if desired) in a Dutch oven over medium heat to 350 degrees F. Fry chicken, in batches, skin-side down, until golden brown, 4 to 5 minutes. Turn and fry until golden brown on the second side, 4 to 5 minutes. Transfer to prepared baking sheet and bake until an instant-read thermometer inserted in the thickest piece registers 165 degrees F. Let stand, on rack, 10 minutes before serving. Serve warm, at room temperature, or chilled.