Place it at the end of a setup, after the reveal has landed, so it closes the moment instead of opening one. For a longer reaction, follow it with the What Da Dog Doin sound, then cut to the Nope Meme sound to shut the scene down.
Über diesen Sound
This is a brief 1.25-second clip built around a single odd vocal burst, the drawn-out nonsense sound spelled Aoeii, with no words or music around it. It lands as sudden and silly, the kind of noise that makes a normal moment feel deliberately wrong. That quick, off-kilter energy is what makes it useful as a reaction, cutting through a scene before anyone has time to explain it.