Blocked drains: they’re the bane of every home, and they always seem to strike at the worst possible moment.
Whether it’s the kitchen sink gurgling after a Sunday roast or the bathroom basin refusing to drain after a grandchild’s visit, a slow or smelly drain is a problem most of us have faced.
And while the internet is awash with DIY hacks—some more effective than others—there’s one humble laundry staple that plumbers are quietly swearing by. Best of all? It’ll only set you back about $5.
Why do drains get blocked in the first place?
Before we get to the magic fix, it’s worth understanding why our drains get blocked. In the kitchen, it’s usually a combination of grease, food scraps, and soap scum.
Over time, these build up on the inside of your pipes, narrowing the passage and slowing the flow of water. In the bathroom, hair, toothpaste, and soap are the usual suspects.
If left unchecked, these blockages can lead to unpleasant odours, slow drainage, and even costly plumbing bills.
The classic hack: Does vinegar and bicarb soda really work?
If you’ve ever Googled ‘how to unblock a drain’, you’ve probably come across the old vinegar and bicarb soda trick. The idea is simple: pour bicarb soda (baking soda) down the drain, follow it with vinegar, and watch the fizzing chemical reaction.
While it’s satisfying to see, many people find it doesn’t always clear stubborn blockages—especially those caused by grease.
Why? As Daniel Smith from Cal’s Plumbing explains, it’s all about chemistry. Grease is acidic, and so is vinegar. When you combine two acids, you’re not really breaking down the problem.
Baking soda is alkaline, which helps, but it’s not always strong enough for the toughest jobs.
The plumber’s secret weapon: Washing soda
Enter washing soda—also known as sodium carbonate. This unassuming white powder, often found in the laundry aisle under brands like Lectric, is a plumber’s best-kept secret for clearing drains.
It’s more alkaline than baking soda, making it far more effective at cutting through greasy, stubborn blockages.
You can pick up a 1kg bag of Lectric Washing Soda at Woolworths or Coles for around $5, or at The Reject Shop for a few cents less. Not only is it affordable, but a single bag will last you for months.
How to use washing soda to unblock your drain
Here’s the step-by-step method recommended by both plumbers and the makers of Lectric Washing Soda:
- Boil a kettle of water and pour it down the blocked drain to help loosen any gunk.
- Slowly add one cup of washing soda directly into the drain.
- Follow with another cup of boiling water.
- Let it sit for five minutes to allow the washing soda to work its magic.
- Flush with more boiling water and check if the water is draining freely.
If the blockage persists, repeat the process. You should notice an improvement with each treatment.
For ongoing maintenance, pour a cup of washing soda and hot water down your drains once a week to keep them clear and odour-free.
When to call in the professionals
While washing soda is a powerful DIY solution, it won’t fix every problem.
If your drain remains blocked after a couple of attempts, or if you suspect a more serious issue (like tree roots or a collapsed pipe), it’s time to call a licensed plumber.
Persistent blockages can sometimes indicate a bigger problem that needs professional attention.
More than just a drain cleaner: Other uses for washing soda
The best part about buying a bag of washing soda? It’s a true multitasker around the home. Here are just a few ways you can put it to work:
- Laundry booster: Add a scoop to your wash to help remove grease and brighten whites.
- Soak stained clothes: Dissolve in warm water and soak overnight to tackle tough stains.
- Clean your washing machine: Run a hot cycle with washing soda to remove built-up grime.
- Bathroom cleaner: Use it to scrub basins, tiles, grout, and even shower curtains.
- Kitchen helper: Remove brown stains from mugs, clean oven surfaces, boost dishwasher detergent, and tackle burnt-on grease (just avoid using it on aluminium).
A word of caution
Washing soda is a strong alkaline, so always wear gloves when handling it, and keep it away from children and pets. Avoid using it on aluminium cookware, as it can cause discolouration.
Share your tips and experiences
Have you tried washing soda to unblock a drain, or do you have another tried-and-true method? What’s your go-to hack for keeping your pipes clear? Share your stories and tips in the comments below—your advice could help a fellow reader avoid a plumbing disaster!
Also read: Hate scrubbing? Experts say this $10 Bunnings product will make cleaning a breeze
