Mrs Martin’s Probiotic Flush Cistern Block 100g


Who does not like a toilet that smells fresh and clean? This biodegradable, earth-friendly toilet cleaner prevents odours and blocked drains in any toilet. Yes, even an off-the-grid toilet flowing into a septic tank can now smell fresh! The millions of indigenous microbes in this block starts degrading dirt in the water as soon as you flush, keeping your septic tank or local sewage plant working well. Everything else in this block is non-toxic and degrades in less than 28 days so you can rest assured you are doing no harm. Neither to your system nor to the environment.

Directions for use:
Ready to use. Remove from wrapper and place in cistern. Replace as necessary. Depending on how often toilet is flushed, one block can last a month.

Earth friendly bleach that is responsible, intelligent and safe.

Responsible because our ingredients are readily biodegradable to OECD 301 standards and we offer refills to eliminate single use plastic.

Intelligent because our detergents include indigenous, friendly microbes that produce the enzymes necessary to degrade dirt.

Safe because our products are non-toxic and approved by The Allergy Foundation of South Africa.

Our products rehabilitate grey water and are ideal for use in septic tank systems.

Our products are PET FRIENDLY.

Free from

  • Chlorine bleach
  • Triclosan
  • EDTA
  • Phosphates
  • 2-butoxyethanol
  • Phthalates
  • Paraben
  • Ammonia
  • High VOC glycol ethers
  • Formaldehyde


Sodium dodecylbenzene sulphonate, Sodium chloride, Citric acid, Anionic surfactant, perfume, More than 10 million CFU/ml of naturally occurring, indigenous, safe bacteria (Bacillus spp).

Customer Reviews

Based on 17 reviews
Wilien West
Flush blocks

Amazing smell and freshness in bathroom.
Toilets feel sanitized and clean all the time.

So effective

As it says on the wrapper - it prevents drains from blocking. This product really impressed me because we have had endless issues on our property with blocked drains. Now we've noticed a difference, since I used these. From now on, I will be ordering the bulk pack. Love the color and the overall effectiveness of these!

Tracy Fry
Probiotic Flush Cistern Block

I love the smell and I love what it does for my toilet and septic tank, I do have a problem with the dark blue colour - I really do not like it. It looks like the water in mobile toilets. I have got the dispenser that you put the block in to reduce the blue colour to a lighter shade, but the dispenser is very difficult to adjust to the lightest blue. Now, something else that I must remind you of, anyone who has had colon cancer will advise you to check your stool all the time to ensure that there is no blood in the stool, this is also something that Doctors recommend. With the blue being such a deep blue, you cannot do this, you can see nothing in toilet. So, there is also a health reason for a no colour or very light blue colour. Sorry to be so graphic, but this is a fact.

Let me say again that the product itself is awesome, I will keep on buying it

Helen Patrick
Very good

The flush cistern block is very convenient to use, and, as with all Mrs Martin's products, I love the fact that it is earth-friendly.

Marina T.
The whole bathroom smells fresh!

The whole bathroom smells fresh!