Super explanation, Faldage!! Onion juices go straight up!!

And now I'll explain why the tongue sticking out also works:

You see, your tongue stick out like a big ol' diving board in front of your face, right? And those juices going straight up that Faldage just taught us about get blocked by your big ol' diving board tongue, you know? They just cain't make it past that tonguey barrier.