Preheat the oven to 180*C. Place cereal, rice cakes and pretzel sticks in a 4L baking pan and stir to mix. In a small bowl, stir together the oil, Worcestershire sauce, chili powder, dry mustard and garlic powder until well mixed. Spoon chili powder mixture over cereal mixture and toss to coat. Bake for 20 minutes or until crisp and golden, stirring several times.