Baking soda and vinegar drain cleaning is an often suggested do-it-yourself fix for common plumbing problems. The theory behind this is that combining vinegar and baking soda causes a chemical reaction that produces a bubbly foam that can help dissolve obstructions and unclog drains. But even though this technique is widely used, there isn't much proof to back up the idea that vinegar and baking soda work well as drain cleaners. Combining these two substances can occasionally cause more harm than good.