For the usual person who does not have an underlying condition Moritz's 2 LFs with no stones may be an indication that they've all come out. I have done LFs for about 20 years and I would get to the point where no stones came out and for a while, sometimes for several years I would not become congested again. Then I would start doing LFs again and get out many more stones. There were several things that would have helped me keep from making more stones - going on a strict gluten free diet because I had undiagnosed Celiac Disease, keeping my body slightly alkaline rather acid which I do now with diet and baking soda, using more parasite herbs to get them, especially flukes, out of my liver and small intestine, using various treatments to restore normal intestinal flora.
As far as I could tell I did not pass any hard calcium stones, maybe because I was not adsorbing calcium. 6 years into the gf diet I think that I am excreting calcium in the bile as sludge, as I still have not seen any hard stones. Lately I've been eating more apples and that seems to be reducing the bile sludge which is quite gritty and toxic.
Lately I've been doing LFs every 3 to 6 months and do get out more stones. I keep taking several parasite herbs as I think that not all of the flukes have been killed off. Clark wrote that it is not possible to completely cleanse the bile system if there are still parasites in there.