flog something to death
From Longman Dictionary of Contemporary Englishflog something to deathflog something to deathBritish English informalREPEAT to repeat a story or use an idea etc so often that people become bored with it They take a good idea and flog it to death. → flogExamples from the Corpusflog something to death• It was a good story a month ago, but the newspapers have really flogged it to death.