When you’re gearing up for a well-deserved vacation, your to-do list probably includes all the usual suspects: unplugging appliances, double-checking that all the doors and windows are locked, emptying the trash, setting the thermostat, and maybe even asking a neighbor to water your plants. But there’s one small, often-overlooked trick that could save you a big headache when you return home—placing an upside-down glass over your sink drain before you leave.

It might sound odd at first, but this simple hack can prevent foul odors, unexpected moisture, and even uninvited pests from greeting you at your door after a relaxing getaway. Read on to discover why this works, how to do it, and what else you can do to make sure your kitchen stays fresh and clean while you’re away.
Why the Sink Matters When You’re Gone
Most of us don’t give much thought to the kitchen sink beyond daily use. But when you leave your home empty for a few days or longer, your sink and its drain can become a source of some unwelcome surprises.
The P-Trap Problem
Your sink’s drain system includes a “P-trap”—a curved piece of pipe designed to hold water and block sewer gases from drifting up into your kitchen. As long as you’re running water regularly, that trap stays full and works just fine. But if you’re gone for a week or more, the water inside the P-trap can slowly evaporate. Once it dries out, there’s nothing stopping the not-so-pleasant smells from the sewer system from wafting right up into your home.
Moisture and Pests
An unused drain can also be a magnet for tiny household pests, like fruit flies, drain flies, or even ants and cockroaches, especially during warmer months. These critters are always searching for damp, dark places to breed or find food—and a kitchen drain that’s been sitting still for a week is practically an invitation.
The Upside-Down Glass Hack: How It Works
This method is refreshingly simple and requires zero fancy gadgets:
- Clean your sink and drain thoroughly.
- Lay a sheet of paper towel or a few squares of toilet paper over the drain opening.
- Take a clean drinking glass and place it upside-down directly on top of the drain, completely covering the paper.
That’s it. No special suction, no moving parts—just gravity and a good seal.
Why Is This Effective?
The upside-down glass acts as a barrier that blocks air from moving freely in or out of the drain. The paper towel helps make a tighter seal and keeps any small bugs from squeezing in. Unlike sink stoppers, which can get loose, shift, or dry out, the glass stays put thanks to its weight. This physical barrier helps trap any odors below the sink line and keeps out curious pests.
Step-by-Step: Prepping Your Sink Before You Leave
Want to make sure you come home to a fresh, clean kitchen? Here’s a quick pre-vacation checklist for your sink:
1. Clean the Sink
Wash down the entire basin, faucet, and drain area with soap and hot water. Get rid of any food scraps, grime, or grease that might attract bugs or cause odors.
2. Deodorize the Drain
Pour a cup of hot white vinegar down the drain. Let it sit for an hour or two to help dissolve any lingering smells or buildup inside the pipes.
3. Flush the Drain
After the vinegar treatment, flush the drain with plenty of hot water to clear out loosened debris and give the P-trap a final fill.
4. Freshen with Lemon
Rub a half-lemon over the sink and drain area for an extra burst of freshness. The natural oils in lemon help neutralize odors and leave a clean scent.
5. Dry Everything
Use a clean towel or paper towel to dry the sink thoroughly. This step helps discourage bugs and prevents water stains.
6. Cover the Drain
Place a sheet of paper towel or a few layers of toilet paper directly over the drain opening.
7. Seal with the Glass
Position an upside-down glass, mug, or cup right over the paper-covered drain. Make sure the glass completely covers the opening.
Why Not Just Use a Regular Sink Stopper?
You might be wondering why you can’t just use your standard sink stopper or plug. The answer? Most stoppers aren’t airtight. Over time, they can loosen or let air (and odors) pass through. They’re also not always effective against determined insects that can squeeze through tiny gaps.
In contrast, the upside-down glass is heavy, doesn’t rely on a rubber seal, and creates a more reliable physical barrier. Plus, you probably already have everything you need in your kitchen—no special shopping trip required.
The Benefits of This Method
- Eco-Friendly: No harsh chemicals, no disposable plastic gadgets—just simple household items.
- Free: Uses things you already have on hand.
- Safe: Won’t damage your sink, pipes, or plumbing hardware.
- Versatile: Works in any sink—kitchen, bathroom, laundry room, or even bidets.
- Peace of Mind: Return home to the same clean, fresh kitchen you left behind.
Frequently Asked Questions
Does this work in every season?
Yes! Whether you’re traveling in summer (when pests are more active) or winter (when dry air can speed up evaporation), this method is effective all year long.
Can I use something other than a glass?
Absolutely. Any sturdy, upside-down cup or mug that completely covers the drain will work. Just make sure it’s wide and heavy enough to stay in place.
Should I do this in my bathroom sink or shower?
If you’re going to be gone for more than a week, it’s a great idea to repeat the trick in bathroom sinks, bathtubs, or shower drains.
How long does it take for a P-trap to dry out?
Depending on climate and air flow, it can take anywhere from a few days to a couple of weeks for the water in your P-trap to fully evaporate.
Extra Tips for an Odor-Free Homecoming
- Garbage Disposal: Run it with cold water and a few lemon slices before you leave. Make sure it’s clear of any debris.
- Take Out the Trash: Never leave trash, compost, or recycling inside—it’s an open invitation for bugs and bad smells.
- Close Toilet Lids: This helps keep odors out and prevents pets from drinking toilet water.
- Leave Cabinet Doors Ajar: In very humid climates, leaving cabinet doors slightly open can help prevent musty odors from developing.
Coming Home Should Feel Wonderful
There’s nothing worse than walking in after a trip to find your kitchen smelling off or, worse, playing host to a new colony of insects. The upside-down glass trick is a tiny effort with big payoff: peace of mind, a fresh-smelling kitchen, and one less thing to worry about as you pack your suitcase.
So next time you’re headed out for vacation—whether it’s a long weekend or a month-long adventure—spend a few extra seconds on this simple hack. Your nose (and your nerves) will thank you when you get back.
Sometimes, it’s the smallest details that make all the difference in home care. Safe travels and enjoy your trip—your kitchen will be waiting, just the way you left it!
Disclaimer:
The information and advice provided in this article are intended for general household use and informational purposes only. Results may vary depending on individual home conditions and plumbing systems. Always exercise caution when working with cleaning products or kitchen appliances, and consult a licensed plumber or pest control professional if you experience ongoing issues with odors, pests, or plumbing. The author and website are not responsible for any damages or losses resulting from the use or misuse of the tips described above. Always use your best judgment and follow manufacturer instructions for your home appliances and fixtures.