Cut each chicken breast into 4 strips, lengthwise, and place in a large bowl. In a separate bowl, whisk together 1 1/2 cups buttermilk and hot sauce until blended.
Pour over chicken; mix until chicken is coated. Cover and refrigerate for 1 hour.
Make dip: In a medium bowl, combine sour cream, 1/2 cup buttermilk, blue cheese, vinegar and Worcestershire sauce.
Whisk to mix well. Season to taste with salt and pepper. Cover and refrigerate.
Preheat oven to 350F. Mist 2 large baking sheets with cooking spray. In a food processor, pulse crackers until crushed.
Add seasoning mix and pulse to combine.
Spread cracker mixture on a large platter.
Remove chicken from marinade and carefully dredge each strip in cracker mixture.
In a large skillet, warm 2 Tbsp. oil over medium-high heat until shimmering.
Add half of chicken and cook, turning, until brown and crisp on all sides, 2 to 3 minutes.
Place on baking sheet. Repeat with remaining oil and chicken.
Place baking sheets in oven and bake until chicken is cooked through, 8 to 10 minutes.
Serve chicken hot with celery and blue cheese dip.