Start to take hits where you cough like a little scag. I guarantee that you'll get used to taking big bong hits if you do this. Coughing also makes blood rush to your head causing thc to get there faster giving you a good high. I'm able to clear a 5' 5" bong easily completely full of smoke. But it could also be from me being a bagpiper and having a huge lung capacity...who knows!?