You did your first flush!!!! I think it is always the hardest, even to get the nerve to do it is a major undertaking. My first flush was a few stones and sludge, then subsequent ones got out larger ones and eventually old dark stones. Keep flushing and let us know how you do. I plan on flushing every 2-4 weeks for a year total. I have gotten out >1500 stones so far in 8 flushes since June.