Preheat the oven to 400 ̊. Prick the potatoes all over with a fork, rub with a little vegetable or olive oil and bake on a foil-lined rimmed baking sheet until tender when pierced with a knife, about 1 hour. When the potatoes are almost done, combine the mayonnaise, buttermilk, sour cream and Worcestershire sauce in a small bowl and stir until smooth. Stir in the blue cheese and 2 tablespoons of the chives; season with salt and pepper. Refrigerate until ready to serve. Melt the butter in a medium skillet over medium heat. Whisk in the hot sauce. Add the chicken and cook, tossing, until heated through, about 2 minutes. Keep warm. Split open the baked potatoes lengthwise; press the ends together to open them up. Top each potato with 1 tablespoon of the blue cheese dressing and season lightly with salt. Use a fork to mash the dressing into the potatoes. Top with the chicken mixture, then another tablespoon of dressing. Sprinkle with the celery and carrot. Top with more blue cheese and the remaining 2 tablespoons chives. Serve with the remaining dressing.