A good flush always feels rewarding. :-) Now I remember having some kidney area pain that started after flushing away back. I figured my kidneyes just wanted some attention.
Celery seed tea is a good way to clean the kidneys of sand and debries. 1 teaspoon Celery
seeds to 1 cup of boiling water, let it steep for about 15 minutes. I think I drank one cup in the mornings and one in the afternoons for several days. That cleared the problem, no more pain.
Celery seeds are available at a herb store, or you may buy them in the spice section at a supermaket. Good luck, Giz.