A viral travel hack suggests placing a sheet of paper and an upside-down glass over your sink drain before leaving home. The idea is to stop sewer odors and insects from entering through the drain while you’re away. Although the hack has gained attention, experts say the concept is based on a real plumbing principle—but the method itself isn’t very effective.
The reason behind the hack involves the P-trap, the curved pipe beneath sinks, tubs, and floor drains. It holds water that acts as a barrier against sewer gases and pests. As the article explains, **”The water within the P-trap creates a physical barrier between your home and the large sewer system outside.”** If a drain goes unused for a long time, that water can evaporate, allowing unpleasant smells or insects to enter.
For most people, this isn’t a concern during a short trip. P-traps usually stay filled for at least a couple of weeks, though hot, dry conditions or rarely used drains can cause the water to evaporate faster. That’s why the issue is more common during vacations lasting three weeks or longer.
While covering the drain may sound helpful, **”the method depicted in the photo is not a reliable means of sealing your drains.”** An upside-down glass rarely creates a tight seal, and the paper can become damp or shift out of place. As the article notes, **”Unless the upside-down glass creates a tight seal over the drain opening, it’s unlikely to do much of anything.”**
A better solution is simple. Before leaving, run water through every sink, shower, and tub for 10 to 20 seconds and flush all toilets to refill the P-traps. If you’ll be away for an extended period, seal the drains with built-in stoppers, rubber plugs, silicone drain covers, or even plastic wrap. For extra protection, a small amount of mineral oil can be poured into the drain to slow evaporation. These simple steps help maintain the water seal and reduce the risk of odors or insects without relying on a viral hack. As the article concludes, **”You won’t need to perform any complicated hacks or glass-balancing acts.”**
