When my dad was a Scout they were on some kind of hike, like all good Scout Troops do. One of the Scouts needed to fertilize the forest really badly and found a good looking spot. After doing his thing the Scout grabbed a handful of leaves to use to clean up with. The leaves turned out to be poison ivy and for rest of the trip he spent scratching his rear end.
The lesson … know what kind of leaves you are using before cleaning yourself else you may have an embarrassing itch.