flog
/ˈfläg/
verb
to beat with or as if with a rod or whip
to criticize harshly
to force or urge into action : drive
The sailors were flogged for attempting a mutiny.
He was flogged in the press for failing to take action.
idiom
to keep talking about a subject that has already been discussed or decided
to waste time and effort trying to do something that is impossible
I don't mean to flog a dead horse, but I still don't understand what happened.