Place butter in a small, microwave-safe bowl and microwave on high for approximately 90 seconds or until butter is completely melted. Add onion dip mix, garlic powder, sea salt, and soy sauce to the melted butter and stir until mixture is uniform. In a large, microwave-safe bowl, combine sandwich crackers, Joe’s O’s, pretzel nuggets, and cheddar rockets. Pour seasoning mixture over the snack mix slowly. Gently stir with a large spoon until the snack mix is evenly coated. Microwave finished snack mix on high for 1 minute, remove it from microwave, and stir again. Place mix back in microwave and microwave on high again for 1 minute. Stir gently, allow to cool, and serve. Store remaining snack mix in an airtight container in the refrigerator.