The Forgotten Pre-Vacation Ritual: The Truth About the “Upside-Down Glass” Sink Hack (And How to Truly Protect Your Home’s Peace)

 

There is a very specific kind of peace that comes from locking your front door, knowing your home is safe, and stepping into your car for a well-deserved getaway. Whether you’re heading off to visit the grandkids, going on a quiet retreat, or just escaping for a few days to a cozy bed and breakfast, the anticipation is wonderful.

But recently, right before I was about to leave for a week-long trip, I pulled out my phone and saw it: a viral video telling me to cover my sink drains with an upside-down glass or a plastic bag to “stop sewer gas and creepy crawlies.”

My heart immediately started to race. At 73, living alone, I am incredibly proactive about my health. I’m always keeping a close eye on my circulation, trying to understand those sudden, unexplained purple blotches on my arms, and doing everything I can to prevent sudden spikes in my blood pressure that could lead to a stroke or an aneurysm. And let me tell you, the anxiety of wondering, “Did I do the sink hack right? Is my house going to fill with toxic gas?!” is enough to raise anyone’s blood pressure!

So, I put my suitcase down, put the kettle on, and grabbed my favorite mug of chamomile tea to look into the actual plumbing science.

Let’s separate the internet fiction from the old-fashioned, reliable facts, so you can lock your door and leave for your trip with total peace of mind.

The Big Reveal: Why the “Glass Hack” is a Myth

Let’s get right to the bottom of this. The short answer? You do not need to cover your drains with a glass, a bag, or a shower cap.

Here is the fascinating kitchen-and-plumbing science behind why:

The Magic of the “P-Trap”

If you look under your sink, you’ll see a pipe that bends down and then curves back up in a “U” shape before going into the wall. That is called a P-trap. Its entire job is to hold a small pool of water.

That little pool of water acts as a physical, liquid seal. It is what blocks heavy, smelly sewer gases from floating up the pipe and into your bathroom or kitchen. It also blocks drain flies and bugs.

The Real “Forgotten Ritual” (The Mineral Oil Trick)

 

The only time sewer gas escapes is if the water in that P-trap evaporates. Unless you are leaving your house for six months with the heat blasting, the water in your P-trap will not evaporate during a standard vacation!
However, if you are going on a long trip (over a month), here is the forgotten pre-vacation ritual our grandparents used: Pour a tablespoon of cheap mineral oil (or even cheap vegetable oil) down every drain in the house before you leave. The oil floats on top of the water in the P-trap and completely prevents evaporation, keeping the seal intact for months. No upside-down glasses required!
The 3-Step “Peace of Mind” Checklist
Q: What if I already have drain flies in my bathroom?
A: If you see tiny fuzzy flies hovering around your sink, it means there is organic buildup in the pipe above the water line in the P-trap. The glass hack won’t fix this. Instead, pour a pot of boiling water down the drain to flush it, or use a natural enzymatic drain cleaner before you leave for your trip.
Q: Should I cover my drain if I live in an area with a lot of bugs?
A: If you are worried about pests, covering the drain isn’t the answer, as bugs can find their way around plastic wraps. Instead, focus on ensuring your window screens don’t have tears, and use the peppermint oil cotton ball trick under your sinks!
Q: Is it safe to leave the water in the P-trap for a month?
A: Yes! As long as your home is climate-controlled (not freezing cold or sweltering hot), the water in the P-trap will easily last for a month or more without evaporating. If you are leaving for longer than a month, just use the mineral oil trick I mentioned above!
Let’s Travel with Peace of Mind!
I truly hope this takes the worry out of your next vacation. It is so empowering to know that we don’t need to fall for stressful internet hacks when good, old-fashioned plumbing science has already solved the problem for us. By taking ten minutes to run the water, turn off the main valve, and use a little peppermint oil, you are protecting your home and, more importantly, protecting your own heart health by letting go of travel anxiety.
If you try my 3-Ingredient Avocado, Feta & Mint Whip when you get back from your next trip, I would absolutely love to hear how it hit the spot! Do you have a favorite “welcome home” meal that requires zero effort? Drop a comment below to share your wisdom, and please share this article with a friend who is about to travel and might be stressing over those viral sink hacks.
Safe travels, stay healthy, and I’ll see you when you get back!