I did the Clark flush my first three flushes. The first and third produced no stones.
Following the third flush, I bought "The Key to Health and Rejuvenation" by Andreas, and followed most of the advice in his book. This is about more than just flushing your liver and gallbladder.
Flushes 4 through 14 (which I did last night) have produced over 16,000 stones. I'm normally over 1000, with 2500 to 3000 coming out on my fifth flush. The better I eat, the better the flush.
I was very sick before listening to Andreas... candida, etc. I now have most of my health back because of him, and I continue to get better daily.