Why don’t you just try it…? It’s not that hard to do. Just relax your sinus muscles and close your lips, then alternate between using your tongue to fill the space in your mouth pushing air out your nose and moving your tongue out of the way to create a void, sucking air back in. If you can coordinate this while also alternating between closing your sinuses and opening your lips while you create the void in order to suck air in your lips, and then closing your lips and opening your sinus so that the air gets pushed out your nose, then you’ll be able to pump air from your mouth out your nose without using your lungs.