Thanks for the information and encouragement. I needed that!
In the meantime, I had found some information on frequency of flushes in the FAQ section of Liver Cleansing on Curezone. That encouraged me to go ahead, so, 8 days after my 2nd cleanse, I did a third. Unfortunately, I threw up all the olive oil/grapefruit mixture shortly after 1 a.m.! Even so, I expelled numerous small stones and a couple harder ones, about 1/8" dia., that were brown on the outside and filled with a white powder inside. I still don't feel great, but I'm glad I went ahead and did a third cleanse. I do feel somewhat better, certainly not worse.