Powerful Drain Cleaner & Unblocker l 1KG Caustic Soda | Fast-Acting, Heavy-Duty Sink & Drain Cleaner | Strong & Effective | The Original & Best l Works 3x Better Than Bleach (Packaging Varies)

Used it on a blocked kitchen sink and a slow-draining outdoor gully—this stuff works fast. Mixed 100g with 1L of cold water, stirred until dissolved, and poured it straight down. Within 10 minutes, you could hear it fizzing and shifting the blockage. Followed up with hot water and the flow was back to normal. It’s industrial strength, so you need gloves, goggles, and ventilation. The powder reacts aggressively—don’t mess about. It also works well for degreasing tools, cleaning brickwork, and prepping surfaces before painting. I used it to strip grime off a concrete pad and it lifted years of buildup in one go. Packaging’s basic but solid. Lid seals tight, no leaks. Just keep it dry and locked away—this isn’t something you want kids or pets near. ✅ Pros Fast-acting—clears tough clogs in minutes Versatile—drains, tools, brickwork, degreasing Industrial-grade strength for serious jobs Affordable—around £8–£9 for 1KG1 2 3 4 Easy to mix and apply Long shelf life if stored properly ❌ Cons Highly caustic—needs full PPE and careful handling No childproof lid Can damage pipes if misused—follow instructions Not suitable for aluminium or soft metals

This seemed to help the blockage. I’ve used two loads but could possibly use another

Lovely product and worked well. Worth spending money, but you need to be extra careful with mixing it in water thoroughly as otherwise it could cause certain issues if you don’t follow the instructions correctly.

warning: it is highly toxic so keep away from kids/pets and it will eat aluminium fittings and pipes so check first. when your bath drain stops flowing properly, sprinkle some down the hole dry, leave for 5 mins then flow a small amount of water and let it sit. you may hear it hiss and it will get warm as it eats the hair/skin proteins and dissolves the soap. pour some more down and repeat. leave 30 mins and then flush through with plenty of water and viola your drain is clear. leave the water running for 10 mins to flush it all away and job done. each use is about 100g total so 1kg lasts for years. imo don't waste your time with supermarket or branded "eco" drain cleaners they are expensive, terrible and rarely work properly for the stubborn hair/soap blockages (they actually cause environmental damage as you have to use more, every few weeks) especially if a cowboy plumber didn't plumb the drain correctly so lets waste water sit in the pipe... plastic pipes have no issues but if you have metal fittings make sure you wash it all away thoroughly to avoid any potential issues with flux/fittings/rubber etc NaOH is highly corrosive to metals and organics so don't leave it on your skin too long, it'll feel slimy until you fully wash it off. again, keep away from kids, pets, food and eyes ie basic chemical safety and you'll be fine.

Ok but didn't clear my blockage

I'm unsure of the various quality levels of caustic soda, if indeed there are any, but this product performed the task of cleaning / clearing drains very well.

Great. Really helpful to unblock drains.

This is stuff. After following it up with very warm or boiling water, if possible, you want to blast it afterwards with water as it can collect and set . But boiling or hot water should melt it sufficiently.