Re: Things in the vase/base
We screwed around with every damn thing when we first got into hookah years ago. Most of it is a waste.
Milk will thicken the smoke somewhat, but make sure you clean the hell out of it afterward. Had a friend who left his egyptian out over night with milk in the bottle. Had to buy a new bottle. Even then, the hookah was never the same. *Shudder*
These days, I save my drinks for drinking. Tap water works great. A handful of ice cubes helps smooth out some of the harsher flavors (It's basically a requirement for Fumari cola.) But other than that, save yourself the hassle.