Here's a question for you: Do you think you could produce enough wind to blow a ping pong ball out of a funnel?
Did you try? Can't get the ball out?
It's a physics trick. See, the harder you blow, the harder it is for the ball to leave the funnel, thanks to the Bernoulli principle.
Basically, the faster a fluid flows, the less pressure it creates. In this case the fluid is air. When you blow through the funnel you create a current of fast moving air around the ball. That results in a low-pressure zone below the ball that allows the higher pressure zone above it to push the ball down and keep it from rising any farther.
It's the same principle that airplane wings use to create lift.