Place it at the very end of a reaction sequence, after the claim or reveal has finished. Pair it with a record scratch before the moment, or follow it with the Ba Dum Tss button when the flop is meant as a full punchline instead.
Über diesen Sound
A single, very short hand clap lasting under half a second, with no speech or music around it. On its own it feels pointedly lukewarm and sarcastic, like applause offered out of politeness rather than excitement. That restrained, slightly awkward energy is what makes the lone clap read as a dry joke.