Remove one joint from chicken wingettes. Push meat down and remove smaller bone and discard.
In a large saucepan of boiling water, simmer chicken wingettes for 10 minutes. Remove with a slotted spoon and drain on paper towel lined baking sheet.
In a zip top bag, mix together ketchup, Worcestershire sauce, soy sauce, brown sugar, garlic, chili powder and sambal.
Add chicken wings and toss to coat. Refrigerate wings for at least 3 hours, turning occasionally.
To grill: Grill on lightly oiled grill, over high heat, for 20 minutes, turning occasionally, until no longer pink and juices run clear.
Oven: Heat oven to 375 degrees (190 degrees Celsius). Place chicken wingettes on rack over baking sheet. Bake for 25-30 minutes or until no longer pink and juices run clear. Serve immediately