Use it monthly to keep your drain fresh and flowing, but don’t expect it to replace mechanical or enzymatic cleaning for real blockages.

If you’ve ever searched for a non-toxic, budget-friendly way to clear a slow shower drain, you’ve almost certainly seen the same DIY recipe: pour baking soda down the drain, add vinegar, wait, then flush with hot water. But how effective is this fizzy reaction, and what are its real limitations? Let’s break down the science, the correct method, and when you should call a plumber instead. The Science Behind the Fizz Baking soda (sodium bicarbonate) is a weak base, and vinegar (acetic acid) is a weak acid. When they combine, they produce carbon dioxide gas—the fizzing you see—plus water and sodium acetate. This chemical reaction creates turbulence and some pressure, which can dislodge soft debris like soap scum and loose hair. Additionally, the foaming action can help scrub the sides of the drain pipe.