Creosote is quite a nasty smelly chemical generally used to paint fences and sheds. Here is a little advice if you are trying to tackle a creosote stain.

First of all if the item that you are trying to clean is dry clean only then the only solution is to send it off to the dry cleaners pointing out the stain to them.

For everything else eucalyptus oil is your answer. If you have creosote on your clothing or furniture then keep dabbing with eucalyptus oil until the stain is gone. The wash as you would normally do.