Make the Meat Spice Rub and combine it with the apple juice, stirring to blend. Scrape the mixture into a resealable plastic bag, add the chicken, turning to cover, and marinate overnight.
Preheat the oven to 350°F.
Space the thighs evenly on a rack on a sheet pan and bake until cooked through, about 45 minutes. Remove from the oven, cool, and shred the chicken by hand before it has completely cooled; season to taste with salt. Lightly brush the tortillas with oil, spoon ¼ cup of filling in each, roll up, and secure with a pair of toothpicks.
Prepare the Pico de Gallo.
Use a deep fryer or a large skillet filled with enough oil to measure 1 inch deep and heat to 375°F on an instant-read thermometer. Drop 2 or 3 flautas at a time into the hot oil and cook until crispy. If using a skillet, turn the flautas so they become crisp and golden on all sides, 3 to 5 minutes. Drain on paper towels, remove the toothpicks, and serve on a small oval taco plate, folded side down. Sprinkle with crumbled queso fresco, Pico de Gallo, and a drizzle of crema.