Here’s a clear, step-by-step guide for using baking soda to unclog pipes, including when it works best and how to boost its effectiveness. Baking soda (sodium bicarbonate) is a mild alkali. When combined with an acid (like vinegar) or just hot water, it creates a fizzing action that can dislodge soft clogs (grease, soap scum, food particles) without damaging pipes or harming the environment.