FWIW, this
stuff removes the Urushiol oil --which causes the irritation and insane itchingf rom exposure to poison ivy/oak/sumac-- also a bonus a tip earned from a bad case of this -- NEVER take a warm/hot shower after being exposed to poison ivy. It helps spread the oil...
Also, for those who think they are "immune" to poison ivy--you ain't, you're just not allergic to it yet. Repeated exposure can bring on the immune response of the itching and irritation. My dad had never had a case, even though he was out in the woods a lot. Then one year, he managed to catch an ax across his leg while clearing the stuff. That wound basically injected poison ivy into his blood, which carried it through out his body over a week or so. Back then doctors made house calls and my dad was laid up in bed basically in agony. He asked the doc what it would take to cure his suffering. "'bout two weeks" was the response. Dad was allergic to it after that experience.