Prepare Toothpicks: Soak toothpicks in water for about 15-20 minutes to prevent burning during baking. Make the Sauce: In a bowl, combine soy sauce, ketchup, Worcestershire sauce, garlic powder, and onion powder. Stir well to combine.
Place in the preheated oven and bake for 20 minutes. After 20 minutes, brush the water chestnuts with the remaining sauce. Bake for an additional 10 minutes, or until the bacon is crisp. Remove from the oven and serve immediately.