A viral travel hack suggests covering a sink drain with paper and an upside-down glass before leaving home to stop sewer odors and insects from escaping.
While based on the real principle of keeping the “water seal” in the pipe’s P-trap intact when water evaporates over time, experts say this method is unreliable because the glass rarely creates a tight enough seal, and the paper can easily become damp and fail.
Instead of relying on this trick before a long trip, run water through every sink, shower, and tub to fully refill the P-traps, then secure the drains using proper stoppers, rubber plugs, silicone covers, or plastic wrap.
For extended vacations, adding a tablespoon of mineral oil to the drain can also effectively slow down water evaporation and keep pests or odors at bay.
