What's the most passive side hustle you've tried?

"Passive income" gets thrown around a lot online and most of the time it's exaggerated. But I do think some hustles require way less active effort than others once they're set up.

What's the most passive side hustle you've actually tried and was it really as hands-off as people claim? Be honest, I can handle the truth 😅 Would love real experiences over theory!