In 1988 I was out in a heavily wooded area in Dallas, and brushed against what I thought was a 2″ diameter vine as I walked through the trees. Within 1 minute, I developed a very large irritation area on my arm where it had touched me. Went back and looked at the “vine” in more detail, and realize it was a massive poision ivy plant. The only thing I had that I thought might get rid of the irritating oil was Crest toothpaste, so I rubbed it on trying to remove the irritant. Within ~15 minutes, the itching was gone, within a couple of hours, it was difficult to tell where I had touched it.