Household cleaning
Astonish Specialist Mould & Mildew Remover dupe
Why pay around £2.00 for Astonish? The bulk active is Dairy-grade sodium hypochlorite 14% (diluted to 3.5%) — 69% less per working litre than a typical shelf pack.
From the retail pack to the active and the mix
1 · Retail
Astonish Specialist Mould & Mildew Remover
750 ml trigger · £2.00 typical snapshot
Water and fragrance
2 · Active
Sodium hypochlorite and anionic surfactants
3.5% on the label
7681-52-9NaOCl
Bulk Dairy-grade sodium hypochlorite 14% (diluted to 3.5%)
3 · Mix
1 part 14% hypochlorite to 3 parts water
£0.82 per working litre · 69% less than the shelf pack
- Active
- Sodium hypochlorite and anionic surfactants
- CAS
- 7681-52-9
- Dupe
- Dairy-grade sodium hypochlorite 14% (diluted to 3.5%)
- Saving
- 69% / L
Saving is per litre of working-strength mix versus a typical pack price, not versus the DIY kit total. Shop prices move — always check the listing.
Label teardown
What the pack promises versus what the label chemistry actually is.
The marketing claim
“Removes black mould stains in minutes without scrubbing”
The chemical reality
Highly diluted bleach sold with a plastic spray trigger. Diluting bulk hypochlorite costs pennies.
Active vs filler
3.5% Sodium hypochlorite and anionic surfactants · 97% carrier / filler — Water and fragrance
- Typical retail
- £2.00
- 750 ml trigger
- Estimated active cost
- £0.62
- Scaled from bulk £16.50 / 5 litres
- Indicative markup
- 3.2×
- Snapshot maths, not a live shop price
The Marketing Claim & The Catch
A 750 ml trigger pack of Astonish Specialist Mould & Mildew Remover typically retails around £2.00 in household cleaning. That is a UK shelf-price snapshot for the maths on this page — not a live shop quote or a manufacturer RRP. Listings, sizes and deals move. The marketing line is that you are buying a finished lifestyle product, not a weighed chemical.
On the pack: Removes black mould stains in minutes without scrubbing; and Bleach-action cleaner for bathroom grout and silicone seals.
The catch: Highly diluted bleach sold with a plastic spray trigger. Diluting bulk hypochlorite costs pennies.
- “Removes black mould stains in minutes without scrubbing”
- “Bleach-action cleaner for bathroom grout and silicone seals”
Proprietary Blend & Dosage Breakdown
The labelled active is Sodium hypochlorite and anionic surfactants at 3.5%. Everything else in the pack is water and fragrance.
At 3.5% active, most of what you pay for is carrier and packaging. The brand is selling convenience, fragrance and a label — not a uniquely potent molecule.
Branded working strength is whatever comes out of the bottle. The bulk alternative is 14% Dairy-grade sodium hypochlorite 14% (diluted to 3.5%), mixed to 1 part 14% hypochlorite to 3 parts water.
- Labelled active
- Sodium hypochlorite and anionic surfactants
- 3.5%
- Carrier
- Water and fragrance
- Retail pack
- 750 ml trigger · £2.00
The Active Chemical Alternative (Dupe Stack)
The dupe stack is Dairy-grade sodium hypochlorite 14% (diluted to 3.5%) at 14% bulk. Indexed as CAS 7681-52-9, formula NaOCl. Buy it as 5 litres for around £16.50 from Amazon UK.
Working strength: 1 part 14% hypochlorite to 3 parts water. Indicative cost £0.82 per diluted litre — 69% below a typical branded pack on a per-litre basis, before you reuse leftover bulk.
Follow the mixing method and the supplier SDS. Wear the listed PPE. Do not mix incompatible oxidisers, acids or ammonia.
- Pour 200 ml of 14% hypochlorite into an empty 1 L trigger spray bottle.
- Top up with 600 ml of tap water and 1 teaspoon of standard washing-up liquid for surface cling.
- Spray directly onto black mould in tile grout, leave for 10 minutes, and wipe clean.
- Never mix with acids, vinegar or ammonia.
Dilution recipe
0.8 L working batch
Working strength 1 part 14% hypochlorite to 3 parts water. Educational estimate from the listed ratio — check the SDS before you mix.
Chemical
200 millilitres
Dairy-grade sodium hypochlorite 14% (diluted to 3.5%)
Water
0.6 litres
Carrier / diluent
25% concentrate · 75% water by working volume (solids are dissolved into the water share).
Required PPE
Loading calculator…
Side-by-Side Price & Potency Comparison
Head-to-head comparison
| Measure | Retail brandedAstonish | Raw active dupeDupeStack |
|---|---|---|
| Product | Specialist Mould & Mildew RemoverAmazon UK search — listing, not a confirmed seller | Dairy-grade sodium hypochlorite 14% (diluted to 3.5%) |
| Pack / unit | 750 ml trigger · £2.00 | 5 litres · £16.50 |
| Active | Sodium hypochlorite and anionic surfactants at 3.5%Carrier: Water and fragrance | 14% bulkNaOCl |
| CAS number | Not disclosed on pack | 7681-52-9 |
| Working strength | Ready-to-use pack | Dilute 1 part 14% hypochlorite to 3 parts water |
| Cost per litre | £2.67 / L typical pack | £0.82 / L mixed from bulk |
| Headline saving | Baseline | 69% cheaper |
| COSHH / PPE | Follow the branded SDS | Gloves. Chemical-resistant gloves (nitrile or neoprene)Eye protection. Indirect-vent splash goggles — not ordinary spectaclesVentilation. Use outdoors or with mechanical extraction |
Active ingredient and cheaper alternative — FAQ
What is the active ingredient in Astonish?
Astonish Specialist Mould & Mildew Remover is labelled as Sodium hypochlorite and anionic surfactants at 3.5%. The carrier is Water and fragrance. Pack size: 750 ml trigger. The bulk equivalent we index is Dairy-grade sodium hypochlorite 14% (diluted to 3.5%) (CAS 7681-52-9).
Is Dairy-grade sodium hypochlorite 14% (diluted to 3.5%) safe on the intended surface?
Used at the listed working strength (1 part 14% hypochlorite to 3 parts water), the dupe is the same chemistry as the branded pack for kettles, ceramics and washable hard surfaces. That is not a blanket all-clear: read the supplier SDS, wear the listed PPE, keep acids away from hypochlorite, and follow UK HSE/COSHH rules. Wellness teardowns are supplements, not medicines.
Is there a cheaper alternative to Astonish Specialist Mould & Mildew Remover?
Yes. The bulk equivalent is Dairy-grade sodium hypochlorite 14% (diluted to 3.5%) (CAS 7681-52-9). Indicative saving 69% per working litre versus a pack that typically retails around £2.00. Working strength: 1 part 14% hypochlorite to 3 parts water. Live shop prices move.
How do you mix the Specialist Mould & Mildew Remover dupe stack?
Pour 200 ml of 14% hypochlorite into an empty 1 L trigger spray bottle. Top up with 600 ml of tap water and 1 teaspoon of standard washing-up liquid for surface cling. Spray directly onto black mould in tile grout, leave for 10 minutes, and wipe clean. Never mix with acids, vinegar or ammonia.
DupeStack provides chemical concentration data and educational mixing guides only. Wellness pages compare food supplements, not medicines or prescribed treatments. Always review the supplier Safety Data Sheet (SDS) and comply with UK Health and Safety Executive (HSE) and COSHH regulations when handling concentrated substances. Mixing and storage are at your own risk. Some links are affiliate advertisements (Amazon Associates, eBay Partner Network, and Awin when those programmes are live). Commissions do not change listed concentrations or calculator output.
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Indicative DIY stack