I’ve caused a lovely washbasin to crack by pouring boiling water into it. by mistake.
I should have warmed it gently before giving it the shock treatment.
I was under the weather at the time and (obviously) not thinking clearly.
So I think it’s reasonable to warn folk of what might possibly happen re toilet/whatever
I live in a limestone area an use pumice stones regularly
with a bit of elbow grease the ‘stones’ slowly crumble away along with the limescale and everything stays sparkling in bathroom and kitchen 
That will remove the glaze over time making things a bit worse and harder to remove, it’s why dissolving it is generally better. My mother used to buy pumice powder years ago so witnessed this over time. Yes I replaced the pan.
Oh dear! I better stop now 
We use a commercial toilet cleaner which says it’s suitable for use with a septic tank system. It’s Harpic and cleans well Does not seem to remove the shine of the toilet porcelain either
Harpic power plus toilet descaler is 9% hydrochloric acid. Expensive though, just saying.
Hi Corona
Thanks for the information re Harpic Not sure I would trust myself to using something other than a preprepared version of Harpic I am happy to experiment with cooking as I have practiced this for donkeys years now and so far no-one has had a bad reaction to my attempts at making a meal! So far ….
Quite understandable, the brico sheds hydrochloric is 22% so nearly 2.5 times stronger and needs to be treated with respect. Just posted for info.
Thanks for your info anyway, Corona
You really need a phosphoric acid based cleaner like this. It’s a powerful descaler and safe for a fosse as long as you don’t use it too regularly. It’s also doesn’t attack steel. Phosphoric acid is primarily used to remove scale in pipework and macerator toilets.
Coca-Cola=descaler, no wonder I don’t drink it (phosphoric acid) as you said doesn’t hurt steel and from memory there is a rust converter made from it as well.
I remember we used spirit of salts to clean the loo in our first UK home which was in a chalk region so plenty of scale. on everything that used water. OH had to wear a respirator, wear industrial rubber gloves and use a rag held on the end of a thick stick to wipe round the bowl it was that toxic but it worked and the loo became like new after being left to “soak” for a while. A new toilet seat made it better than ripping the whole thing out and buying new. Don’t think you can buy spirit of salts over the counter these days but this was early 80’s
I bought spirits of salts in the UK, maybe 10 years ago. The main ingredient was hydrochloric acid.
Also known as One shot by the package, builders brick cleaner is usually hydrochloric acid.
In the olden days I remember my mum used to use lemon juice and salt as a cleaning agent. I’ve just done a Google search and asked ‘can you use a mix of lemons and salt to get rid of limescale’ and got this answer:
Yes, a mixture of lemons and salt is a highly effective, natural, and eco-friendly way to remove limescale from household items.
. The citric acid in the lemon breaks down the calcium carbonate (limescale) deposits, while the salt provides a gentle abrasive texture to scrub away softened residue without damaging surfaces.
How to Use Lemon and Salt for Limescale:
Faucets and Taps: Cut a lemon in half, dip it directly into coarse salt, and rub it on the tap. For stubborn scale, wrap the lemon-covered tap in a plastic bag, secure with an elastic band, and leave for an hour or overnight.
Stainless Steel Sinks: Sprinkle coarse salt over the sink, squeeze lemon juice over the top, and let it sit for 20–30 minutes before scrubbing and rinsing.
Kettles: Add several lemon slices and a handful of salt to the kettle, fill with water, and bring to a boil. Let it sit for at least an hour, then rinse thoroughly.
Grout and Tiling: Apply lemon juice directly to the affected tiles or grout, let it sit for 10–15 minutes, then apply salt and scrub with a brush.