My late FIL used to take Poison Ivy extract pills every Summer, which were supposed to de-sensitize him to it's affects. I've no idea where one would get them nowadays.
I went through this same treatment with Poison Oak extract when I was a kid. I'm hypo allergic to PO. I was rushed to the ER as a kid when I got exposed to PO and swelled up so much my breathing was affected. Not so much fun.
In So Cal, where I grew up, PO stays actively growing all year so it's easy to spot. Fast forward to years later bought my property in Nor Cal. Decided to trim some bushes along side the road during winter. Didn't realize that is was PO that had lost it's leaves. I woke up the next day covered in PO rash, my eyes were swollen shut and my lips were huge. Fortunately my wife (an RN) was able to give me something to reverse the swelling. Went through three weeks of misery afterwards though.
The soap DIED mentions is great stuff.
IMHO the best way to get rid of it is to pay someone else to do it.
