There was an article a while back about a guy who ingested poison oak in order to develop tolerance for the irritant. https://news.ycombinator.com/item?id=4039

There was an article a while back about a guy who ingested poison oak in order to develop tolerance for the irritant. https://news.ycombinator.com/item?id=40399224 https://news.ycombinator.com/item?id=40399224 I discussed that article with an old-timer here in New England told me that a slightly less extreme version worked for him: letting goats eat the massive growth of poison ivy on his land, then drinking the goat milk for a few weeks or months.