So how do they work? Soda crystals are a water softener and a degreaser rolled into one. When hot water hits them, they create an alkaline solution that breaks down fatty acids (grease) into soap. That soap then dissolves into the water. They don’t violently melt the blockage like acid would; instead, they it.
But are they actually up to the job, or is this just another old wives’ tale? Let’s pull the plug on the science and find out.
If the sink is full of standing water, try to bail out as much as possible so the crystals can reach the blockage.