I use it if I absolutely need to maximize what I'm getting, and when I do I prepare kava first, then mix the geog with some milk, warm up with so lecithin for a bit, then use ice cubes to cool down.
Theoretically will help KL's absorb better, and IMO it seems that some of the 'lactones giving more bodily effects come on better with a source of fat (so if things are heady, milk seems to balance it out a bit).
But for the most part... water works just fine.