Oh my, I get it real bad too. I use a wash called TecNu right away if I suspect I've been it in. Hardly anything works for me. An old-timer told me a while back that his Mom put old time white shoe polish on it for them. Haven't tried it and hope I don't have too!
One year I got it everytime I pulled weeds. After 2 years I realized it was in the bagged mulch I had put in the flower beds. The olis are active for 6 years after the plant is dead.
Good luck.