hey sorry to hear you are having troubles, hope some of this info helps you. I have done over 15 flushes, and i have learned that it is important to follow the instructions. i believe that if you follow the instructions and don't get many stones (or none) then either there are no stones on deck, or more likely (for me) there are one or more LARGE stones slowing things down. possibly the large stones are moving slowly toward the exit each time, but you may be able to speed things up by softening them with something like malic acid (found in fresh apple juice). i have had good results drinking approx. 1 qt of fresh, high quality apple juice per day for 3 or 4 weeks. not sure you need to go that long, but it definitely made a difference. i see many people also reccomend the gold coin grass, but i have never tried it. good luck!