I used berberis and equisetum homeopathically, when I once had kidney stones.
pain from Hell is right. The ER told me to take some tylenol 2 and "come back if it gets too bad", as if they fully expected to do surgery. ( this was before machines that shatter the stones with sonar. ) The homeopathy worked like magic, within a day of taking it, and I passed, without much pain at all, a huge stone.almost the size of my baby fingernail, but 3D. (this would have been much harder for a man to pass) It was fascinating. Hard as rock, with little quartzlike parts. there was probably grit too. It felt like the remedies worked to break down the mass.
The coke would be hard for me to stomach. What do you feel about eating raw parsley? i am thinking more in preventative terms.
Another good kidney thing: sit in a bathtub and consume an entire Watermelon with seeds.( and chew them) The bathtub is supposedly because you will pee alot. Sorry to offend anyone, but we have probably all peed in a lake...I have not tried this, but it sounds like fun in summer, when it is very hot, and the water is cool. And yet more, Celery seed tea.