Wash and pat dry each apple. Place each skewer down the center of each apple. Line a baking sheet with parchment or waxed paper. Dip each apple in the caramel sauce, coating completely. Place on the baking sheet and refrigerate until firm. Dip each caramel apple for a second time in the melted milk chocolate, coating completely. Place on the baking sheet and refrigerate until firm. Dip each apple a third time in the white chocolate, coating completely. Place on the baking sheet and refrigerate until firm. Dip each apple for a final time in the white chocolate, coating completely. Place on the baking sheet and sprinkle each apple with the pecans. Refrigerate until firm and serve.