Sounds like the voice of experience
I have had Poison Oak, Ivy, Sumac or whatever so many times (and really, really bad) as a kid and young adult that I learned what not to use for TP should such a situation arise.Hmm, sounds like you learned the hard way. My Dad did when I was kid.......LOL.......Rough lesson....
Nowadays it get a few spots of it and it’s gone in a couple days.