Yeah, I have read about a 'few' ppl claiming that they have produced stones just by drinking ES...
But in general, propagators of Liver-Flush tell you drinking oil is extremely important to see plenty of stones.
Personally I have never seen green stones with just ES...
Also I have flushed a total of 13 times and have seen all kinds of stones- small, large, pea sized, some long one and I was AMAZED... But I have no interest in seeing those stones now. Because I still strongly believe that they are fake.
That being said, I am still proactive about my health. I drink lots of water, try to daily yoga, I try to invert, and eat healthy. But drinking Oil and ES is not in my list.