In eating ONLY brown rice, you are referring to a Macrobiotic Cleanse which was so stringent that it is not generally recommended anymore. There are some healthier versions which combine the cleansing power of organic brown rice (high in fiber) with veggie and fruit. Ideally this is my favorite kind of diet AFTER or before a Master Cleanse since I LOVE short grained organic brown rice more than most things. Here are a few links to get you pointed in a direction you may want to go. If you want a deeper cleaning feel free to explore the Master Cleanse.
*note from Zoe I use a rice steamer but do not use one that has an aluminum bowl since the aluminum leaches into your food...do not cook in aluminum either for the same reasons....