Place it as the closing verdict after a failed plan or bad decision is shown, then follow it with Nelson's Ha-Ha for extra mockery or the sudden suspense sting before a reveal. It also works after the wrong answer buzzer when a guess goes badly wrong.
About this sound
This is a short 2.2-second voice clip of Donald Trump delivering the blunt line 'they don't know what they're doing' in a frustrated, exasperated tone. It lands as a sharp, dismissive put-down, funny because it sounds so direct and fed up, and it works best as a quick verdict on a plan that has clearly gone wrong.