Many reviewers use a weekly soda crystal + boiling water flush to keep drains clear.
: If the clog is in the U-bend, a drain snake or a wire coat hanger can physically break the "rock" into smaller pieces that can then be flushed away. The Right Way to Use Soda Crystals
Here’s a general review-style analysis of using (sodium carbonate, not to be confused with caustic soda) for a blocked sink, based on common user experiences and effectiveness.
Leo’s error wasn't using the crystals—it was how he applied them. He poured a generous amount of dry crystals directly down the drain and followed it with just a splash of lukewarm water.
: If water alone doesn't work, try pouring a cup of white vinegar down the drain. The chemical reaction (fizzing) can help break up the physical structure of the blockage.
Great for mild, organic blockages – not a miracle cure for tough clogs.