1. Mix 1 tablespoon of baking soda, 1 tablespoon of warm water and 2 teaspoons of oat flour in a small bowl to create a natural facial cleanser that also exfoliates. (Pour 1 tablespoon of rolled oats into a small bowl and crush them with the edge of a spoon until a powder forms if you don't have 2 teaspoons of oat flour on hand.)
2. Rinse your face with warm water. Dip your fingers into the cleanser and apply it to your face and neck using a gentle circular motion. Let the paste dry on your skin for 5 minutes.
3. Buff away the dried cleanser by moving your fingers in a gentle circular motion. The dried paste exfoliates your skin as you buff it away.
4. Splash your face thoroughly with warm water to remove any remaining cleanser. Pat your face dry with a clean towel. [source: SFGate.com]
Bottom line: If you want to try baking soda as a natural exfoliant that's a cheap, eco-friendly alternative, go ahead and experiment. But if you experience a reaction, stop using it immediately.