But when you leave for several days, especially in warm weather, that water can slowly evaporate, breaking the seal and allowing smells—or even tiny bugs—to escape into your home.
By covering the drain with a paper towel and an upside-down glass, you’re slowing down air circulation, which helps keep moisture inside and prevents unwanted smells from spreading.
It’s simple physics: less airflow means less evaporation—and a fresher home when you return.
If You’ll Be Away for a Long Time
If your trip lasts more than two or three weeks, you can take one extra step for longer protection:
After cleaning the sink and rinsing it with vinegar and lemon, pour about one tablespoon of cooking oil or mineral oil into the drain.
The thin layer of oil will sit on top of the water inside the trap, acting as a barrier to stop evaporation completely.
Then, cover the drain with paper and the upside-down glass as usual.
