Boiling Water Down Drain

—sudden expansion that can stress older joints or cause porcelain fixtures (like sinks or toilets) to crack. Joint Integrity:

This is the closest safe alternative. Pour 1/2 cup of baking soda down the drain, followed by 1 cup of white vinegar. Cover the drain to force the reaction down. Wait 10 minutes. Chase it with (not boiling—around 120°F to 130°F). The fuzzy, expanding foam dislodges organic matter without melting PVC. boiling water down drain