This obviously won’t help you at this point, but I found a YouTube video years ago of a guy that recommend dish soap and a wash rag on exposed skin immediately after working near any area that may have poison ivy. After getting into what I believe was sumac cleaning off a fence line, it’s been my go-to method after doing any yard work near the wood line. Haven’t had an issue since. Supposedly, the dish soap cuts the oils and the rag moves it off the skin as opposed to just moving it around like a loofa would. Hope you get some relief soon buddy.