Yeah it would be more for a black swan kind of event, where it is uncertain if it will go back up again.
I found a backtested strategy with buying 30% out of the money puts with 4 months to expiration, that are rolled over after 2 months, having an annualised cost of 0.78%, which is pretty low. I would rather have SPX options instead since they have wider opening times for trading than options on SPY. https://seekingalpha.com/article/43...ack-swan-events-strategy-pays-off-in-long-run
This is a very complicated question which is the most research part of options theory. Even this proposal is very tricky as it may not earn on a selloff. Most tail/black swan funds fail. The rest obfuscate their pnl performance.