If the sink is still draining slowly after one treatment, don't panic. Some clogs are stubborn. Here is what to do:
After the time has passed, remove the stopper. Boil another kettle of water (or run hot tap water for PVC pipes). Pour the water down the drain to flush away the loosened debris and the remaining baking soda mixture. how to clean sink drains with baking soda
This is the most important step! You want the fizzing reaction to be forced down the pipe, pushing against the clog, rather than fizzing up into your sink. If the sink is still draining slowly after