Place it at the reaction beat after the visual gag, then follow with the Laughing Dog Meme Sound Button for a second wave, or precede it with Nelson's Ha-Ha! Sound Button when one character is mocking another before the whole group joins in.
About this sound
This is a 2.3-second burst of fast, frenetic human laughter, written out in its name as rsrsrs, the Brazilian text laugh. The giggling is rapid and uncontrolled, stacking laugh over laugh without words. It feels gleefully unhinged and contagious, the kind of laugh that makes a silly moment feel even funnier because the reaction itself is over the top.