I've had more than my share of messes, but I don't know that I've ever gotten two-cycle fuel in my hair. . . . .
I've heard Coke suggested for getting it out of clothing. I like Fast Orange for getting the smell off my hands, but not sure about hair - I'd be afraid that stuff might fry your hair.
Good ol' sunshine and fresh air has always been good for getting that sort of thing out of jackets and jeans . . . .
Just some thoughts.
seriously, wonder if the same method to remove skunk odor would work?