Preheat your oven to 425°. Spray a baking sheet with cooking spray. Set aside.
Pop the fish into the freezer for 10 minutes while you prepare the other ingredients. You want the fish very very cold, but not fully frozen.
Combine the yogurt, the sweet pickle relish, the lemon juice, the milk, and 1/8 teaspoon salt. Your kids will love you. Cover the sauce and refrigerate until ready to serve.
Pulse the bread in a food processor until it is a fine crumb.
Heat a large skillet over medium heat. Place the crumbs in the skillet and toast 3 minutes, stirring frequently.
Ready a standard breading setup with three shallow dishes: Flour. Buttermilk. Crumb.
Remove the fish from the freezer and sprinkle with 1/2 teaspoon salt and pepper. Coat the fish sticks in flour, then buttermilk (no remaining dry spots, please), and finally the crumb.
Arrange the fish sticks on the coated baking sheet, evenly spaced, and mist them evenly with cooking spray.
Bake for 15 minutes, or until the breadcrumbs are crisp and the fish flakes easily when tested with a fork.
Serve with the sweet pickle yogurt for dipping.