I've done 4 flushes and have not gotten out any sizable stones. Mostly chaff and about 20 tiny stones. Like me, some people have very congested livers, and it's gonna take more than just doing a flush to loosen it up to come out. It depends on your diet, medications, exercise and probably more things that I'm not aware of.
You didn't have anything come out? Not even chaff or greenish/yellowish bile? Keep doing it, it will eventually loosen and come out.