If there’s one thing that will make you feel like you’re living in a horror movie, it’s a full-blown cockroach infestation. And trust me, I’ve been there. Luckily, I’ve also discovered a foolproof way to get rid of them for good. No chemicals, no expensive exterminators, and most importantly, no immune super-roaches coming back with a vengeance. The secret? Diatomaceous Earth (DE).
Now, if you’ve never heard of DE before, buckle up. I’m about to walk you through my battle with cockroaches—how the usual extermination methods failed me, how I stumbled upon this miracle powder, and how it actually works to eradicate these pests for good.
The Infestation That Changed Everything
Back in 2012, I was staying with a family member during the two-year transition before my BIG move to Australia. She decided to upgrade to a fancy side-by-side fridge but went the budget-friendly route and got a refurbished one. All was well—until a couple weeks later when I noticed “tiny little bugs” on the kitchen counter.
At first, I brushed it off. It was summer, and a couple of bugs weren’t unusual. But within days, they started looking…different. Bigger. Weirder. My gut told me something was wrong, so I did what anyone does—I Googled it. That’s when I learned we were dealing with German cockroaches (Blattella germanica) and that they reproduce at an alarming rate.
We panicked and did what most people would do: cockroach bombs. Big mistake. Instead of wiping them out, we sent them scattering to all corners of the two-story house - plus the much utlised full basement. The infestation got worse. Then we called in an exterminator—twice. And guess what? That didn’t work either. It had the opposite effect - like pouring gasoline on a raging inferno.
At this point, we were on the verge of a breakdown. This spotless, meticulously clean home (like OCD-level clean!) had become a roach motel, and nothing was working. That’s when I went down a deep research rabbit hole and found something interesting—scientific studies on diatomaceous earth.
What is Diatomaceous Earth (DE)?
DE is a naturally occurring, powdery substance made from the fossilized remains of microscopic algae called diatoms. It looks like fine dust to us, but under a microscope, it’s basically tiny, razor-sharp shards of glass. And that’s exactly why it works so well on cockroaches.
Unlike chemical pesticides that cockroaches can become resistant to, DE physically destroys them. When they walk through it, it clings to their bodies. Cockroaches are obsessive groomers, so they end up ingesting it—which shreds their insides and dehydrates them to death. It also cuts through their waxy exoskeleton, making them lose moisture until they literally dry out. And because they unknowingly carry it back to their nests, it wipes out the entire colony.
The best part? They can’t develop immunity to it. It works the same way every single time.
The Moment I Knew It Was The Real Deal
Armed with my newfound knowledge, I went to a local farm supply store and bought a bag of farm-grade diatomaceous earth. I dusted every crevice, behind appliances, in dark corners—anywhere I thought cockroaches might be hiding. Then we left for a couple of days.
When we came back? Dead cockroaches. Everywhere.
I’m talking piles of them. They had come out of hiding, desperate for water, only to succumb to the DE. It was the most effective thing we had tried, and from that moment on, I became a DE evangelist.
How to Use Diatomaceous Earth to Get Rid of Cockroaches
After using DE successfully in multiple homes (including my first rental in Australia, my partner’s daughter’s apartment, and as a first step purchasing our house), I’ve perfected the method. Here’s how to do it right:
1. Get the Right Type of DE
Make sure you buy food-grade diatomaceous earth (not the industrial kind used for pool filters). Food-grade DE is safe for humans and pets but deadly for insects. It's a good idea to also wear a dust filtering mask over your nose and mouth - you do not want to breathe the DE into your lungs. Keep it out of your eyes as well - DE has a drying effect. Fun Fact: Although you’ll want to protect your lungs & eyes while using the product, food grade DE can be taken internally by both humans and animals to exterminate pesky critters (parasites!) from the intestines as well as eliminate toxins from the digestive system. You can read about my experience with DE for health issues here.
2. Dust Lightly (Less is More!)
You don’t want to dump piles of it around your house. Cockroaches will avoid thick clumps. Instead, use a powder duster or a small sieve to apply a light, even layer in places they travel:
Behind the fridge
Under the stove
Along baseboards
In cabinets (away from food)
Near plumbing (under sinks and behind toilets)
3. Keep It Dry
DE only works when it’s dry. If it gets wet, it loses its effectiveness. So don’t spray water or cleaning solutions in treated areas.
4. Be Patient
It doesn’t work instantly - although my first experience saw results in two days. You’ll start noticing dead cockroaches in a few days, and within a couple of weeks, the infestation will be completely gone. Homes that have used DE based on my recommendation have remained cockroach-free, aside from the occasional one that might wander in from outside or hitch a ride in a bag or box.
5. Leave a Barrier
Even after the roaches are gone, leave DE in hidden areas (like attics, behind appliances, and under cabinets) to prevent future infestations.
Why DE is Better Than Chemicals
No Resistance – Cockroaches can’t adapt or become immune to DE.
Non-Toxic – Safe for pets and humans (just don’t inhale the dust).
Long-Lasting – It never expires, so once it’s in place, it keeps working.
Affordable – A single bag lasts forever and costs way less than exterminators.
Final Thoughts: DE is a Game-Changer
Since discovering diatomaceous earth, I’ve used it to successfully wipe out cockroach infestations, and I’ve helped countless people do the same. It’s the real deal.
If you’re battling roaches, skip the sprays and bombs—go get yourself some DE. You won’t regret it.
Have you tried diatomaceous earth before? Let me know your experience in the comments!
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