Yes tomato juice works, but Massengill works much better. Two ounces in a gallon of water, pour over dog letting it soak in throughly, wait 15 minutes, rinse with plain water and then shampoo with his usual shampoo.
eta: The best is a mix-it-yourself concoction. In an empty milk jug, mix 1 quart of 3% hydrogen peroxide, 1/4 cup baking soda, and 1 teaspoon liquid soap (pet shampoo will work). Wet dog with water and apply mix to his coat. It will bubble. Leave on for 3 to 4 minutes and then rinse throughly.