I did three when I was still in pretty bad condition and found that after the first one my post-lunch afternoon drowsiness virtually disappeared.
I didn't get tons of 'stones' out with the first one, although I did get a few dozen. The disappearance of my afternoon drowsiness combined with the fact that I hear so many people complaining about the same drowsiness leads me to believe that most Americans' gall bladders/biliary tracts are clogged up, resulting in poor bile flow and thus drowsiness after eating.
Anyway, to answer your question, I would have to say "Yes" they are safe, and a good thing, since bile flow is one of the factors that helps keep candida in check naturally.