Mix the olive oil, parsley, and garlic in a small bowl and set aside. Drain, rinse oysters and set aside. Mix fish fry, garlic salt and black pepper in a gallon zipper bag. Add oysters, a few at a time and shake to coat evenly. Heat oil until hot over medium-high heat in a deep pan. Remove enough oysters from the bag to cover the bottom of the pan and add them to the hot oil. Fry until golden brown and the edges of the oysters are curled. Remove oysters and drain on paper towels for 2 minutes, then put them in a large bowl.