I got my biggest ones out in my 13th LF.
It has something to do with the gallbladder's ability to contract more forcefully after- on the average- 10 LFs( oce you unload the lot from the common billary duct).
I almost gave up flushig after my 11th and 12th Liver-Flush did not produce anything
(I thought I was done), but in this 13th one, I felt very little movement or fluttering(where I usually feel that), so I was shocked to pass 6 large - walnut size- round stones, again, without much effort.
After that I never again had such large ones... but other junk and sludge.