Dawn dishwashing detergent is what's used to clean up animals from oil spills. Use a 1:70 ratio to water. This is from a organic chemist friend of mine. If that doesn't work, I'd suggest a buzz cut. It'll grow back and maybe if it bothers him enough, you can use it to convince him to stay out of the Desitin next time.
She looks like my little Cindy Lou Who again (and not Bowser from Sha Na Na!)