Few household problems are as unpleasant as a sewer smell coming from your shower drain. It’s strong, persistent, and can quickly make one of the most used rooms in your home unbearable. Luckily, there’s a surprisingly simple and effective method to get rid of this odor—and all you need is a plastic bottle. Here’s how it works and why it’s so effective.

Why Your Shower Might Smell Like a Sewer

The bathroom is one of the most frequently used rooms in any home. It’s a place where hygiene and cleanliness should always come first. However, despite regular cleaning, it’s often in the bathroom—especially in the shower—where bad odors start to appear. That musty or sulfur-like smell rising from the drain is a clear sign that something isn’t right in the plumbing system.

There are several reasons this can happen. One of the most common is the buildup of soap residue inside the drain. Even though soap is meant to clean, many bars and liquid soaps contain fatty substances that don’t dissolve completely in water. Over time, these residues cling to the sides of the pipes, where they accumulate grime, trap hair, and begin to rot, creating that unmistakable “sewer” odor.

Another frequent culprit is hair. Hair and body hair naturally fall off while showering and, when they go down the drain, they easily get stuck. As they accumulate, they mix with soap scum, dead skin cells, and other organic material, forming a sticky mass that blocks the smooth flow of water. This buildup can quickly become a breeding ground for mold and bacteria—both of which release foul smells as they grow.

Sometimes, the smell can also be due to plumbing issues, such as a dried-out P-trap (the U-shaped pipe beneath your drain). This section of pipe is designed to hold a small amount of water at all times, which acts as a barrier to stop sewer gases from coming back up. If it dries out due to infrequent use, the gases can escape freely, filling your bathroom with an unpleasant odor.

Whatever the cause, one thing is certain: when the smell becomes noticeable, it’s time to act quickly before it gets worse.

The Bottle Trick: A Simple Solution for a Stubborn Problem

Among the many home remedies people have tried, one of the most effective and environmentally friendly involves using just a plastic bottle, some bicarbonate of soda (baking soda), and citric acid. Together, these ingredients create a powerful chemical reaction that not only eliminates odors but also helps clean and unclog your pipes naturally.

What You’ll Need

• 1 large plastic bottle (preferably 1 liter or more)
• 250 grams of baking soda
• 150 grams of citric acid
• 1 liter of warm water
• A small towel or cleaning cloth
• A kettle or pot of hot water

Step-by-Step Instructions

1. Prepare the Cleaning Solution
   Start by pouring one liter of warm (not boiling) water into your plastic bottle. Add 150 grams of citric acid to the water, then close the bottle and shake it gently until the powder is completely dissolved. Citric acid is a natural, biodegradable acid often found in lemon juice, and it’s excellent for dissolving limescale and soap residue in pipes.
2. Add the Baking Soda
   Next, take about 250 grams of baking soda and pour it directly into the shower drain. Baking soda is a mild alkaline cleaner that helps neutralize odors and loosen dirt and grime.
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3. Pour the Citric Acid Solution
   Wait a few seconds after adding the baking soda, then slowly pour the citric acid solution from your bottle down the drain. The mixture will start to fizz and bubble—that’s the natural chemical reaction between the acid and the base. As it fizzes, it releases carbon dioxide, which helps dislodge dirt, grease, and other debris stuck inside the pipes.
4. Let It Work
   Cover the drain with a wet towel to keep the reaction contained inside the pipe and let it work for about 30 minutes. This gives the solution time to penetrate deep into the drain and dissolve the residue that’s causing the smell.
5. Flush With Hot Water
   After 30 minutes, boil some water in a kettle or pot and carefully pour it down the drain. The hot water will rinse away the loosened grime and any remaining cleaning solution, leaving your drain clean and odor-free.

Why This Method Works

This home remedy is based on a simple but powerful principle: the reaction between baking soda (a base) and citric acid (an acid) generates carbon dioxide and water. This bubbling action physically lifts and breaks down grime, grease, and organic matter clinging to your pipes.

Meanwhile, citric acid also acts as a natural descaler, dissolving mineral deposits like calcium and magnesium that can build up over time, especially in areas with hard water. Baking soda, on the other hand, neutralizes acidity and eliminates odors, leaving your bathroom smelling fresh without the need for harsh chemical cleaners.

Together, these two ingredients create a non-toxic, biodegradable cleaner that’s safe for your plumbing and for the environment.

Additional Tips to Prevent Bad Smells in the Future

• Clean the drain cover regularly. Remove trapped hair and debris every few days.
• Avoid pouring greasy or oily substances down the drain. Even residues from body oils and bath products can contribute to buildup.
• Run hot water after every shower. This helps flush out soap scum before it hardens.
• Keep the bathroom ventilated. Proper airflow prevents moisture buildup and mold growth.
• Use this cleaning method once or twice a month. It’s gentle enough for regular maintenance and will prevent future odors from forming.

With just a simple bottle and two inexpensive household ingredients, you can say goodbye to that unpleasant sewer smell for good. Not only will your shower smell fresher, but your pipes will stay cleaner and last longer—proving once again that sometimes, the simplest solutions are the most effective.