This story was told to me by a man in my herbalism class.
He was a self-sufficient fellow who went out in the Fall to cut his own wood for heating in the Winter. On this particular day he was cutting fallen logs with his chain saw. He was getting tired but didn't want to quit until he'd done as much as possible. His chainsaw slipped and cut into his leg leaving a would three inches long, a quarter inch deep and the width of the saw blade (chain saw blades can be the width of a finger). The wound hurt badly!
But, he was an herbalist in a field of yarrow. He grabbed a generous handful of leaves and chewed them mushy. He stuffed his wound with them. The pain and bleeding stopped. He tied his poultice in place with a handkerchief and went back to work.
This is not something I would have done, but he wanted his wood.
A couple hours later he was satisfied with what he'd accomplished and put his saw away. Then he checked his wound and found it was already closing. He chewed a fresh wad, and tied it in place.
When I saw him two weeks later, the scar looked like if was from an old wound rather than a recent one.
This guy did almost everything wrong, but because he knew yarrow, he came out of it lucky.