As with many discoveries this too was an accident. It was an experimental burn ointment that he mistakenly carried to a drowning incident. A frantic young mouse had grabbed the flask from his hand and administered it to the algae collector who had fallen from his boat.
When the dead boatman jumped up gasping for breath, many mice ran away afraid, but Nettle-stem danced for joy and started composing the ingredients poem as he walked back to his workshop. That poem is taught to all academically minded mice as part of their schooling, and the brew is produced on a regular basis and the freshest batch sealed and kept close at all water activities.