I’ve used an herb called “chanca piedra”, which means “stone breaker”. It relieves kidney stone pain and dissolves the stones so they pass out of the body with little or no pain.
I read about it online and used it myself and gave some to my husband when he was in pain. It completely relieved his pain and we saw the stones in the bathroom toilet after they had passed. They were very small. We wouldn’t be without it now. It is used in Ayurvedic medicine with great success.