I have been taking gravel root, hydranges, marshmallow in liquid extracts, in Stone Free ( a combination of turmeric, gravel root, dandaline, ginger etc) for 6 weeks. I also took herbal diuretics for 2-3 weeks (parsley, juniper berries, uva ursi, chamomile). While the herbs have helped with the pain from kidney stones, they did nothing to remove them. I asked a couple of herblists if hydrange did not work for any of their clients. I was assured by both that it always works. It didn't for me.
I am afraid I may have incurred kidney damage in waiting for all this to work.