ok this part doesn't rhyme. Grab a double handfull of leaves and simmer them in water for at least 40 minutes. When the water is nice and green , dip in cotton balls or rags and wash over inflamed areas. Takes some sting out and helps dry out the oils/blisters too. It's not a cure all but will reduce inflamation and help reduce time in itchy heck.
what it is and looks like: http://en.wikipedia.org/wiki/Manzanita
This is an old family recipe. which means we aren't the only ones I have passed this on to cub scouts and friends , my wife is a fanatic for it cause she is so reactive ad passes it on at every volunteer lecture she gives for the Land Trust. They do a lot of mucking about in chaparral up here, which means poison oak every 10ft and Manzanita about every 150. If you can't find it or get it and are desperate, use vinegar or salt water. It burns, like a dilly. Worst day of my life (ok, one of them) infected with poison oak, we went to the ocean. umm, yeah. Ran into the water, ran back onto the beach with parts on fire. 1 hour later, poison oak didn't bother me no more. yeesh. But hey, it was done. no mas itch, muy, muy bueno.