Proper hydration of the voice - it is not enough to drink water!?

I live in a very dry and high-heat environment. Low humidity and always-on AC for majority of my time. I have been having my voice go out and needing to have a strong cough quite often, so decided to look at the basics of vocal hygiene, that is, keeping hydrated.

I came across this link which says that "You need to keep in mind that any liquid you drink does not touch your vocal cords, in fact, if it does will will start coughing as it went down the wrong way!". It was a shocker (for me) that hydration by drinking water works like this.

Is this true? How effective is the technique mentioned of hydration by nebulizer? Are there other hydration techniques?