Unless you cause harm to others (like accidentally starting the next pandemic), how could you ever punish someone for treating themselves? π€£
We don't, as far as I know, make cutting your own arm off illegal and I fail to see how this is different.
PS: I'm not arguing against you, just noodling philosophically.
A well-made and safely launched firework has a way lower chance of returning to earth than a 7.62 bullet.