I do not have any major kidney problems either, however, I am doing Liver Flushes and it is recommended to do one every 4 flushes. The reason for this is when liver flushing, a lot of toxins get stirred up in your body and they can overwhelm the kidneys. The only problems I recognize is low back pain occasionally as well as those annoying white bumps around the eyes. (By the way, I had a big one crop up in the outer corner of my eye recently and it went away quickly. They usually hang around for awhile. I have another one that has been there so long I don't even remember it not being there. Maybe it will go next.)
You can get all of the herbs pre-measured and ready to go to make the kidney cleansing tea that Andreas recommends at presentmoment.com. Instructions come with it. It is enough for a 15-20 cleanse which is what is recommended.