This is the best stuff I have found for the bumper crop of Poison Oak found in Oregon

http://www.allergies-asthma-sinus-relief.org/products/poison-oak-soap.php

My son breaks out in the stuff if he just looks at it. The doctor reccomended it last time he got into some and it worked very well. Everytime we are in an area where the Poison Oak is found we make him use the soap to limit his reactions.