I had a teacher who made us go outside and cut our own willow switch when we needed whooping (and I mostly did).My granny always sent me outside to get a switch
So the first time I went out there I found a really thin switch and cut it off (all us kids had a pocketknife, of course) and brought it back. She raised welts on the back of my legs with that thing and DID IT EVER STING!!!
So after that, I found the thickest one I could find and cut off, and brought it back. I figured she'd be ashamed to beat me to death with a club. She stepped to the door and threw it outside. That was when I learned she kept a stash of used ones and nailed me with that super-whippy flexible one which had stung so bad before!