I have done so many flushes in my last thirteen years that I lost the count.
I have never used the stone breaking/ dissolving herbs. The only thing I have unintentionally used is turmeric powder, which I take everyday and ate in my food, every single day, except when I am fasting. Apple juice and apples are another food I eat regularly.
So far I have never had any trouble, so many 3cm stones came out easily.
My flush is successful, in that some stones came out. Most about 3/4 to 1/2 cm.
Only different thing I am experiencing is I have a headache, left lobe, and I never even get headaches.