2 pounds unpeeled large or jumbo shrimp
1 cup vegetable oil
1 cup lemon juice
2 teaspoons dry Italian salad dressing mix
2 teaspoons seasoned salt
1 teaspoon seasoned pepper
1 teaspoon Worcestershire sauce
4 tablespoons brown sugar
2 tablespoons soy sauce
1/2 cup chopped scallions
Wash shrimp and drain on paper towels. Mix oil, lemon juice, salad dressing mix, salt, pepper and Worcestershire sauce. Place shrimp in bowl and cover with marinade. Marinate in refrigerator 2 to 4 hours or overnight, stirring occasionally.
Lift shrimp from marinade with slotted spoon and push onto skewers. Place on charcoal grill about 6 inches from hot coals. Grill about 10 minutes, turning once and brushing with marinade. Pour remaining marinade into pan. Stir in brown sugar, soy sauce and onion. Heat to boiling.
Serve as a dip for shrimp.