Most people treat vacation prep like a checklist: empty the fridge, set the lights on timers, adjust the thermostat, water the plants, double-check the locks, and tell the neighbors you’ll be gone. We take care of all the obvious tasks. But there’s one small detail almost everyone forgets — a detail that often leads to that musty, sour smell lingering in homes after a week away.
It’s the sink.
Most of us think of the sink as nothing more than a place for dishes, brushing teeth, or dumping leftovers. But when a house sits dark and empty, that harmless basin becomes a doorway for sewer gases, moisture buildup, and even pests crawling up from the pipes. All of this happens quietly while you’re lounging on a beach or exploring a new city, completely unaware of what awaits you at home.
Fortunately, there’s a simple, zero-cost hack that seasoned homeowners swear by. No gadgets, no chemicals, no effort required:
Lay a paper towel over the drain and place an upside-down glass on top.
That’s it. A paper towel and a glass. It seems almost too simple to matter — but it works, and here’s why.
Every sink has a P-trap — the curved section of pipe under the drain that holds a small pool of water. This water acts as a barrier, keeping sewer gases and pests out. It works perfectly when the sink is used regularly. But when you’re gone for days or weeks, the water gradually evaporates. Once it’s gone, your home becomes vulnerable to everything the trap is meant to block.
And that’s when the problems begin.
Without water in the trap, foul-smelling gases like methane and hydrogen sulfide rise straight up from the sewer, causing that unpleasant rotten-egg odor you notice when you return. The dark, moist interior of the drain becomes a breeding ground for mold, mildew, and bacteria. And insects — drain flies, gnats, ants, even roaches — can crawl up the pipes. You won’t see them while you’re gone, but they’re ready to explore the space once the barrier is gone.
This is why homes often smell “off” after vacation, even when everything looks clean.
The upside-down glass trick addresses all of it.
Place a paper towel or small square of toilet paper over the drain opening, then cover it with an overturned glass. This creates a lightweight physical barrier that blocks gases, moisture, and pests. It doesn’t interfere with the water in the trap enough to speed evaporation, and it allows just enough airflow to prevent condensation.
Some assume a sink stopper should solve the problem. On paper, it makes sense. But rubber stoppers warp, shrink, dry out, or lose their seal. Some even trap moisture underneath, encouraging mildew growth. Others pop out unexpectedly. A glass avoids all these issues: it doesn’t warp, doesn’t react to moisture or temperature, won’t stain, and is already sitting in your cupboard. If an insect tries to crawl up, it hits a wall. If sewer gases rise, the towel blocks the odor entirely.
You can turn this into a simple pre-vacation ritual:
Clean the sink thoroughly — remove food particles and soap scum.
Pour half a cup of white vinegar down the drain to disinfect and cut buildup.
Let it sit for an hour or two, then flush with hot water.
Rub a cut lemon around the drain for a fresh scent.
Dry the sink completely with a towel.
Lay a paper towel over the drain.
Place an upside-down glass on top.
It takes less than a minute, costs nothing, and prevents the most common cause of post-vacation smells.
People who use this hack swear by it. Some cover every sink in the house; others only the bathrooms or kitchen. You can even place glasses over shower drains for extra protection. It works with stainless steel, porcelain, composite — any drain. Plus, it’s environmentally friendly: no sprays, no chemicals, no disposable traps. Just a cup and a scrap of paper you’d throw away anyway.
Imagine coming home after a long trip. You drop your bags, inhale — and the house smells exactly like it did when you left. Not stale. Not sour. Just clean. The air feels fresh, the bathroom doesn’t hit you with damp funk, the kitchen smells neutral.
That small luxury — that peace — comes from a thirty-second trick.
Vacation prep isn’t just about leaving. It’s about returning, too. Walking into a fresh, calm home keeps the good mood going long after your plane lands.
Some habits seem trivial. But this one prevents sewer odors, stops insects, protects your plumbing, and makes your return more pleasant — all for free.
Next time you’re heading out for a trip, check the lights, water the plants, unplug electronics — and don’t forget the sink. Paper towel. Glass. Simple. Effective.
Small habit. Big payoff.
And when you walk back through the door and breathe in fresh, clean air, you’ll know it was worth it.