A proper protocol for detox starts with something that is obvious. Hydrate. Drink a glass of water before beginning the sauna session. The higher the temperature will be, the more water should be consumed before, during, and after the heat therapy.
You should drink a full 16-20 ounce glass of water prior to your session. You could also drink a non-sugar sports drink or better yet coconut water. Coconut water has the added advantage of being loaded with electrolytes and all the nutrients needed for your body to assimilate the fluid completely and quickly.
Avoid sugary drinks, sodas, coffee, or fruit juices with added sugar. Your body will want to sweat out toxic matter from itself and will need a lot of fluid to perform this task well.
How important is this? The Holistic Healing Centre, located just outside Sydney Australia has a good brochure describing how to best use their saunas. And the largest section has to do with hydration:
Stay Hydrated! Most people do not drink enough water, to begin with, and now that you are using a far infrared sauna and sweating, it is even more important to stay properly hydrated. A good rule of thumb is to drink between half an ounce and an ounce of water for each pound you weigh. For example, if you are 150lbs, you will drink 75 to 150 ounces of water from the time you wake up until the time you close your eyes at night.
When exercising or using our sauna you will need to increase this water. It is important to drink water during the hour before you enter the sauna. This will also aid in the detoxifying process.