There was a previous posting about invasive species in Oregon and I did a bit of Googling. I came up with a strange coincidence...
Benzythonium Chloride, Copper Sulfate, and 409 Degreaser are each recommended for cleaning boots and waders. But the benzylthonium chloride chemical is made here in Oregon and, surprisingly, the company also markets it as a treatment for Poison Ivy ! So carrying along this 1 item for 2 purposes might be worthwhile.