All of my bettas eat the Hikari food, and their water hardly ever gets cloudy - its one of the best foods. They do tend to be picky, and sometimes won't eat for a few days. But they will eat eventually. They can go for a while without eating (I think up to a week or more but don't quote me on that).

As far as the cloudy water, the uneaten food probably has something to do with it. But it depends on how big the bowls are. Yes, bettas can survive in the little pint-sized glass bowls, but at least a half gallon is best for them. All of mine are in one over a gallon. The smaller the bowl, the quicker it clouds and the more you have to clean it.