I think the key to a good shot is that you have to get up close. No standing 50 meters away, surreptituously snapping pics with a long telephoto. Maybe put on your silly foreigner cap and make a big joke of buying a big pack. Ask them if they could teach you how to wrap up some betelnut. After you’re all friendly and chatty for a while, then you whip out the camera and snap a shitload of pictures. After 15 minutes, they’ll start to ignore you and you’ll have natural looking pictures.
If you have a blog or anything of that sort and instantly want a bazillion hits, you could forward that to Boing Boing, who seems to post anything having to do with betelnut, no matter how weak it is.
At least that’s how I’d approach it. Perhaps it wouldn’t work. I’d try it myself, but there are hardly any betelnut beauties where I live.