Wild! My friend Jake did something similar for his tiny baking newsletter. He started using subject lines like "Your oven is judging you" and "Butter's dark secret." His open rate went nuts, and he got emails from people who said they signed up just to see what crazy thing he'd say next.
That "Butter's dark secret" subject line idea is so good, lol. I tried similar weird titles for my hiking group's email blast last year. Used stuff like "Your boots are plotting against you" and "The trail wants you to fail," and our opens shot up like crazy. People started forwarding them around just to see what I'd say next, it was wild.