I had the same experience without even taking the olive oil. I was using "Chanca Piedra" and also taking Standard Products "Beta Food'.......and eating apples and consuming apple juice......
I passed 3 monsters using this method. At first I would drink the Epsom Salt water and pass a lot of stones that way. I havent used olive oil in a flush for some time. I now think if you are using Chanca piedra or GCG you can get rid of stones without olive oil or Epsom Salts . It is really interseting how soft they become (the stones) and different shapes they take. However they are unmistakably stones.
I recently bought the pill form of gold coin grass from oriental Products and had NO results. I cheaped out over the 11 dollar shipping charge from sensible health.
I dont know if this works for everybody though. I know I am loaded with stones.....