We are talking about smoke, not liquid. We need to call mythbusters to verify if what you are saying is really true. I just don't see it.

Why is it hard to understand? The cavity of your mouth can act as an air bladder independent of the lungs.

In phonetics this is called velaric airflow:

Velaric refers to another kind of airflow that is generated just within the oral cavity, and which doesn’t involve pulmonic airflow coming from the lungs. Instead it uses suction to create differentials in air pressure. Here’s how it works:

If you seal off air within some space, then increase the volume of that space – then the air pressure inside that space will decrease, and be less than the atmospheric pressure outside. If you then break the seal, air rushes in to equalise the pressure. The sudden equalisation of air pressure makes a short sharp noise.

The speech sounds made with this type of airstream are what we know as ‘clicks’.

There are two main ways that clicks can be formed: one seals the entire oral cavity, the other traps a small pocket of air against the roof of the mouth. We’ll call these ‘lip clicks’ and ‘tongue clicks’. Scroll down to explore each type separately.

"http://australianlinguistics.com/airstream-mechanisms/velari...

There is also glottalic airflow: Using the larynx to create an airstream. The larynx can bob up and down (you’ll have noticed this when you swallow). With a sealed oral cavity, bobbing the larynx down lowers air pressure and sucks air in. Sounds made this way are called ‘implosives’. Bobbing the larynx upwards increases air pressure and forces air out. Sounds made this way are called ‘ejectives’.

No myth buster needed, we can do that stuff with our mouth. Learning Sanskrit is said to be structured in a way that we learn all the humanly possible pronounciations (i doubt that it really is fully complete).

A good introduction to phonetics is "A Practical Introduction to Phonetics" by J.C. Catford. Totally recommended. Getting an understanding of how we use voice was really enlightening.

Thanks for this thorough explanation. And thanks to everybody else for patiently answering my questions.

I smoke cigars occasionally....I don't inhale any smoke. Before puffing I inhale a little air, close my throat, then pull the smoke into my mouth via suction on the cigar, then exhale to blow the smoke out of my mouth.

The previous straw analogy is accurate. It's the same effect with water via straw and smoke via cigar.

Smoke, liquid, doesn't matter. The same mechanism applies. You use your cheeks to draw in the smoke.