Bring 4 cups water in large saucepan to boil. Plunge oysters into boiling water. Cook 10 to 15 seconds, until edges begin to curl. Remove with slotted spoon to paper towels to drain. Blend cornstarch with 2 tablespoons water until smooth. Stir in oyster sauce, soy sauce, and salt. Set aside. Heat oil in wok until hot. Add wine, oysters, garlic, green onions, and ginger. Stir-fry 15 seconds. Drain off any excess liquid that accumulates. Stir in reserved sauce. Stir-fry 1 minute, just until sauce bubbles and thickens.