The American Indians indigenous to the Appalachians would use the grayanotoxins in mountain laurel and rhododendron as a fishing technique. It worked like this:

  • Find a deep hole in a small to medium creek that is followed by a good run of shallows.
  • pick several basketfuls of rhododendron or mountain laurel leaves.
  • Crush up the leaves in your hands as you dump them into the water.
  • Someone should stand in the upstream shallows of the creek, to keep the fish from escaping upstream
  • Everyone else should wait with their baskets in the downstream shallows.

The toxins from the leaves will leech into the water, knocking out the fish. They'll float to the surface, easily scooped up in the shallows. It's like a low-key version of grenade fishing or telephone fishing. I'm not sure if I'd want to eat fish gathered this way, especially considering bonnet's grayanotoxins writeup.