A "cuuf" is a wet, blow of air. Often, a "cuuf" can be made possible by pumping air into the apparatus, sealing it up for 7-10 seconds, doing this one more time, but instead of holding it in, pour a little bit of water on the apparatus. Finally, let it go. This experiment is often said by scholars to be the best.
by Funky_Monkey January 26, 2021