I'm one of the friendly natives and never chewed and spit it out. And than bottle it. White boys story.
Aussies have a pretty good quality of it, as they do in Hawaii (go to the smaller islands for better grade) Extract powder gives more bang for the buck. And there is a Kava cola just about anywhere you go in the Pacific. But you have to drink a few bottles/cans before any affect, all depending on the size. Drink it fast, right away.. We call it 'ava where I'm from. Really mellow stuff but you seem more focused. Not going to boost you up or anything like that. Some of that stuff that is supposed to be pure Kava Kava has stems, leaves and even grass mixed in with it. Make sure you buy the root it's self.
To me, using extract was just like drinking a 40oz but you stay alert and feel pretty cool. Only bad affect I heard about is that it may make the inside of you mouth and maybe nose feel numb. A slight burn for some guy's. And with too much of it over time, some liver problems. It's a legal supplement so might be able to get the real stuff on the internet. Not too sure about your local health food stores though. Probably a weaker blend here on the mainland.