Place the 12 chicken tenders in a shallow bowl and pour in 1¼ cups dill pickle juice (use a little more if needed) so the tenders are completely covered. Cover the bowl and refrigerate for 8 hours to marinate.
After marinating, drain and discard the pickle juice. Remove the tenders and pat them completely dry with paper towels.
In a medium bowl, beat together 1 large whole egg and 1 large egg white. Add ½ teaspoon Kosher salt and freshly ground black pepper to taste, and whisk until combined.
In a shallow bowl, combine ½ cup seasoned bread crumbs and ½ cup seasoned panko bread crumbs.
Working one tender at a time, dip a dried chicken tender into the egg mixture to coat it completely, then transfer it to the breadcrumb mixture. Press the crumbs gently onto the tender to help them adhere, then shake off any excess. Place the breaded tender on a clean work surface or plate. Repeat until all tenders are breaded.
Generously spray both sides of each breaded tender with olive oil spray. If not cooking immediately, arrange them in a single layer so the coating stays crisp.
Preheat your air fryer to 400°F.
Working in batches if needed, arrange a single layer of tenders in the air fryer basket without overlapping. Cook for 10 to 12 minutes, flipping the tenders halfway through cooking, until the coating is crispy and golden and the chicken is cooked through.
For a toaster-oven–style air fryer, use the same 400°F setting and cook for about 10 minutes (check doneness and adjust time if needed).
ALTERNATE OVEN METHOD: If using a conventional oven, place tenders on a baking sheet in the lower third of a 425°F oven. Bake 8 to 10 minutes, flip the tenders, then bake 6 minutes more, until crispy and cooked through.
Remove the tenders from the air fryer or oven and serve immediately.