Cook 1/2 cup chopped onion in 2 tablespoons butter until tender. Combine with 3 cups cooked rice and 1/4 cup snipped parsley. Cut about 2 inches of heavy center vein out of 12 large cabbage leaves. Immerse leaves in boiling water about 3 minutes or just until limp; drain. Sprinkle generously with salt. Place about 1/4 cup of the rice mixture in the center of each leaf; fold in sides. Fold end so they overlap atop rice. Place, seam side down, in 12 x 7 1/2 x 2 inch baking dish. Combine 1 (24 ounce) can vegetable juice cocktail and 1 tablespoon sugar. Pour over cabbage rolls. Bake, covered, in 350 degree oven for 1 hour. Before serving, garnish with dairy sour cream. Sprinkle with crumbled, crisp-cooked bacon. Serves 6.