I experienced the same exact scenario you did and I got PO all over my legs, having penetrated my heavy duty nylon hiking pants due to wetness. Urishiol may be an oil but it can definitely absorb through clothes with water. In my case I didn't kow I had hiked through the leaf-less PO vines and so I didn't wash off quickly (more than 3 hours). I got a real bad case of it and scarring. Pics of this are on ---- [ removed by editor - spam site ] if you're interested, LMK.