I haven't taken them yet, but I've read up on chinese herbal medicien, ayurvedic, and naturpath for years and she answered the same questions/objections I had so I respect her knowledge a lot.
I did the flush without anything to dissolve the stones or open the ducts as I had permanent kidney damage, so Epsom Salts etc. aren't a good thing for me. However, I suffered very little. Didn't get any stones that I could see, but I'm feeling sooooooooooooo much better now!!! Since you KNOW you have a large stone I highly recommend that you dissolve it as much as possible before the flush.