Having had a similar experience over the alps on air italia, this is why I never ever undo my belt unless I have to. The sign went on and 5 seconds later I felt myself physically leave the seat as we hit the worst turbulence I had ever felt. I rediscovered my appreciation for the rosary that day.
Not being Catholic, I looked up 'the rosary'. Which lasted longer...it, or the turbulence? https://www.theholyrosary.org/howtoprayrosary (for example) was an interesting read, as was your comment.
Tends to be faster if you say it in Latin.