Combine 1/2 cup of baking soda and 1/4 cup of table salt to make a natural scouring mixture. Pour 1 cup of warm distilled white vinegar down the sink. Flush the drain with hot water for 30 seconds. Check whether the overflow pipe still smells. Insert the tip of the turkey baster into the overflow pipe. Click to see full answer. Likewise, how do I get rid of the smell in my sink overflow? Stick the funnel in the overflow hole in your sink. Pour the baking soda down the funnel. Next, slowly pour the vinegar down the funnel. Let this sit for about 15 minutes so the baking soda and vinegar can work their deodorizing magic. Carefully flush the sink with the boiling water. Beside above, how do you get rid of smelly drains? Pour baking soda and vinegar down the drain: Run hot tap water for several seconds, and then turn the water off. Dump one cup of baking soda down the drain followed by two cups of hot vinegar. Let the concoction fizz. After one hour, flush the drain with hot tap water. Also asked, why is there a bad smell coming from my bathroom sink? If an odor is coming from your drain or bathroom water, it might be because of sulfur. To be specific, hydrogen sulfide gas creates the unpleasant smell. It is produced because of bacteria and can be in places such as the ground, the sewage, and/or contaminated water and pipes.What is the overflow drain in bathroom sink?An overflow is an optional feature found in some bathroom sinks. As the name suggests, it helps prevent the sink from overflowing. An overflow is a small opening in the sink, and it works by letting air flow into the drain while the sink is full of water so the sink drains water more quickly.