What worked better for my dogs than Tomato juice was a combination of water, alcohol, hydrogen peroxide, and a squirt of dishwashing liquid. (I don't remember the proportions) It really dries out their skin, but strips the oily skunk nastiness out really effectively. One of my dogs was a 200 pound golden retriever with lots of hair, so when get got sprayed it was really a project.

What always gets me about dogs sprayed with skunk is they usually come home so proud of their nice new smell! pee uuuu..