A plumber’s confession: What’s lurking in the pipes behind your loo is the stuff of nightmares — and it’s the real reason for a blocked toilet

Steve Hudson is kneeling on the bathroom floor of a terraced house in Didsbury, Manchester. The camera is rolling. In front of him lies a sawn-open soil pipe on a plastic sheet. He holds it up and slowly turns it. The inside: an inch-thick, black-brown layer that looks like wet tar.

“This,” says Hudson, “came from a perfectly normal toilet. Three-person household, terraced house, no restaurant, no commercial property. A family who thought their loo was spotless.”

Steve Hudson is a master plumber. 28 years of experience. Over 15,000 toilets repaired, uncovered, taken apart. And he says: “What people think of as clean and what’s actually happening inside their pipes — those are two completely different worlds.”

The nasty truth your plumber never tells you

Everyone uses their toilet daily. Most people clean it regularly — brush, bleach, maybe a rim block under the rim. And then they think: job done.

But what happens behind the porcelain, where nobody looks? Inside the soil pipes that lead from your toilet down to the sewer?

Hudson describes it like this: “Imagine your blood vessels slowly building up cholesterol. Layer by layer, invisible, painless. Until one day the flow just isn’t enough anymore. That’s exactly what happens inside your pipes.”

Biologists call it biofilm. A living layer of bacteria, fungi, limescale, grease and organic residue. It starts forming from day one and grows continuously. Every flush pushes water through — but the biofilm clings to the pipe wall like a ring that slowly closes inward. Scientists sometimes call it “Biofilm Armour” because it is almost impossible to remove with conventional methods.

And here’s the problem: Everything you scrub on the porcelain has zero effect on the biofilm inside the pipes. The surface gleams — the pipes behind it are rotting.

“I always tell my customers: you’re washing the face but not the organs. The toilet looks clean, but the pipes are a catastrophe.”
— Steve Hudson, Master Plumber

The 4 stages of a pipe blockage — and why stages 1 and 2 are invisible

In 28 years, Hudson has recognised a pattern. Every blockage follows the same progression — and it doesn’t start when the water stops draining.

New

Full flow.

Pipe is clean and open. Everything works perfectly.

Month 1–12

Biofilm forms.

Thin layer. No symptoms. Nobody notices a thing.

Month 12–24

Drain slows down.

Gurgling, odours. Drain cleaners only help briefly.

Blockage

Nothing moves.

Emergency plumber: £150–300

Why conventional cleaners don’t solve the problem — and often make it worse

Hudson has seen it all over the years. And he says: none of the common products solve the actual problem.

Toilet Duck, Domestos & Co.: They clean the porcelain. The liquid flows straight through the pipe without any meaningful contact with the pipe wall. It’s like pouring water through a blocked pipe and hoping the buildup dissolves on its own.

Chemical drain cleaners (Mr Muscle, Buster): Aggressive acids that attack the top layer of the biofilm — but also the pipe itself. Old pipes become porous and brittle. Hudson: “I’ve removed pipes that were completely eaten away by chemical drain cleaners. The blockage was gone, but so was the pipe.”

Plunger: Pushes the blockage a bit further down. The biofilm remains completely untouched. The blockage is guaranteed to return.

Drain snake: Bores a hole through the blockage. Water flows again — through a hole in the biofilm. The pipe walls remain completely filthy. Two months later, same situation.

Emergency plumber (£150–300): Usually uses the same snake or high-pressure jetting. The pipe looks better for a few weeks — then the biofilm grows back, because the root cause was never addressed.

The discovery that made Steve Hudson sceptical — then convinced him

In spring 2024, Steve Hudson meets a colleague from Bristol at a plumbing trade show. The man tells him about a cleaning powder that has been making the rounds in the sanitary industry across the Netherlands for several years. A powder you put into the toilet that foams up and dissolves the biofilm inside the pipes from within.

Hudson is sceptical. In 28 years, he has seen too many products that promised everything and delivered nothing.

But the colleague shows him a video: a pipe, completely black inside. Powder in, water added, foam rises. 30 minutes later: the pipe looks like new.

“I watched that video three times,” says Hudson. “Then I ordered a packet straight away.”

The product is called FizzClean.

Why FizzClean works where everything else fails — inside your pipes

The fundamental problem with all liquid cleaners is physics. Liquid flows downward. It follows gravity, runs along the lowest point of the pipe and has barely any contact with the side walls or the top of the pipe. But the biofilm sits everywhere — 360 degrees all around.

FizzClean uses a different principle: foam.

The powder is added to the toilet and activated with warm water. Within seconds, a dense, stable micro-foam forms that spreads through the pipe — not downward, but in every direction. The foam presses against the pipe walls, fills every cavity and completely encases the biofilm.

Then the patented micro-foam technology gets to work:

Step 1: The foam completely surrounds the biofilm and penetrates its structure.

Step 2: Natural enzymes in the foam break down the organic components of the biofilm — grease, limescale, bacteria colonies, organic residue.

Step 3: A normal flush carries away the dissolved biofilm. The pipe walls are clean — like the very first day.

“The first time I put FizzClean into an old pipe, I could literally watch the foam lift the grime off the wall. After 30 minutes the pipe was grey instead of black inside. After the second application, it was clean.”
— Steve Hudson

What most people don’t know: Your pipes are a breeding ground for dangerous bacteria

It’s not just about blockages. What many people don’t know: the toilet is one of the biggest hygiene hazards in the home — and not because of the porcelain.

Scientists at the University of Colorado have proven that every toilet flush creates a so-called “Toilet Plume”. Microscopic water droplets are propelled up to 6 feet into the air. These droplets contain bacteria, viruses and fungal spores — and they come not only from the bowl, but also from the biofilm inside the pipes.

The particles land on your towel. On your toothbrush. On the floor. On every surface in the bathroom.

As long as the biofilm exists inside the pipes, every flush is a bacteria shower for your bathroom. FizzClean eliminates the source — not the symptoms.

FizzClean works anywhere pipes can block

What started as a toilet cleaner works anywhere pipes get blocked and biofilm grows:

Toilet: Biofilm, blockages, odours — the primary use.

Basin: Hair, soap residue, toothpaste buildup in the pipes.

Shower/bath: Hair, shampoo residue, limescale deposits in the drain.

Kitchen sink: Grease, food scraps, oil deposits in the drain.

Washing machine: Lint, detergent residue in the drain hose.

One product for every drain in the house. Instead of five different specialist cleaners that all only work on the surface.

Where is the original available? (Beware of fakes)

FizzClean is available exclusively through the manufacturer’s official webshop. Not on Amazon. Not on eBay. Not at Superdrug or Boots.

Hudson warns explicitly: “On Amazon and eBay, counterfeits are now appearing that look similar but have completely different ingredients. They foam up, but do nothing to the biofilm. In the worst case, they damage the pipes.”

Why not on the high street? Because retailers like Superdrug and Boots would have to double the price as middlemen. Through direct-from-factory sales, the manufacturer can offer the best price — including fresh production, buyer protection and a money-back guarantee.