Mix up 1 quart of 3% hydrogen peroxide, 1/4 cup of baking soda (NOT baking powder), and 1-2 teaspoons of Ivory Liquid soap in a plastic bucket. For very large pets, 1 quart of tepid water may be added to enable complete coverage. Wash pet promptly and thoroughly, work the solution deep into the fur. Let your nose guide you, leave the solution on about 5 minutes or until the odor is gone. Some heavily oiled areas may require a "rinse and repeat" washing. Keep this solution out of your dog's eyes, as it will sting.
Make sure to completely rinse out his coat after using this solution, and pour the remaining solution down the drain, letting the water run down with it for an extra minute.