With my first flush I used grapefruit juice and didn't get any stones out either. I think a lot of the time people don't see stones until subsequent flushes if the liver is very congested, and this was certainly true for me. The second flush i got about 40 small green stones out and the third one I have just done produced about 200 stones (some green & some tan coloured)ranging in size including some which were a lot bigger than the previous flush. The thing I did change after doing the first flush was increasing the amount of olive oil to 150ml, the grapefruit juice to about 250ml and also adding about 50ml of lemon juice. Before the third flush I also took malic acid for the first time (1800mg a day for the 5 days preceeding).