To steal a recipe that has been posted before, this stuff works:
16 oz distilled water
16 oz 3% hydrogen peroxide (regular brown bottle from drug store)
.25 cup baking soda
1 oz scent free liquid soap (the green HS stuff is good)
Pour all ingredients into an opaque container (peroxide doesn't like light) and mix up. Keep the cover loose for a few days otherwise it may pop due to off gassing. This recipe has been all over the web. It is advertised as a great homade scent killer on hunting sites. Lots of sites recommend this stuff for if your dog gets skunked to. I just mixed some up tonight and will be using it this weekend.