One of our Labs got skunked a few weeks ago so we have done a bunch of research. One idea I found in a bunch of sites was to take an empty soda can, put a rag in it and add ammonia. The skunks hate the smell and the rag acts as a wick to keep the smell going for a while.
We haven't tried it yet since the skunks haven't been around but I have ammonia and I will use it next time I see their stinky behinds! Having the girls skunked was nearly unbearable and we DO NOT want to go thru that again!