We had “slave day” at my high school too. They sold off football players for a day to carry your books to class for you, etc.
We had that at our school also...
My girlfriend would not bid on me at the football slave auction...
I ask her why and she said “I have you as a slave every day...Today, I wanted to try someone else...”
She winked at me when she said it...
I think I just stood there with my mouth open....LOL