I have also heard this, however--and you may find this gross, but--you can also get these "stones" out by giving yourself a urine enema. I have used the traditional olive oil/grapefruit recipe and gotten many of the green/tan/white stones out. Alternately, I've given myself a urine enema (half of my own urine and the other half warm water in a full-sized enema bag) and gotten the same green/tan/white stones out.......and no olive oil was involved. If you do administer the enema, be sure to lay on your right side with your right leg pulled up for at least 10 minutes before evacuating the liquid. I personally find this easier and much less time consuming....not to mention--virtually free. I do plan however, to do the traditional olive oil/grapefruit recipe at least once per year. Outside of that, I do a flush weekly.