The product is a big dud and fortunately at least it isn’t expensive.
I bought it ignoring any negative reviews, thinking that with persistence and patience I would get the desired result. But no luck.
The firebrick is porous and once it soaks up smoke and soot, it is hard to clean.
My fireplace is actually one of the easy cases, since it is new and I only had to deal with the burning of one winter and not accumulated soot from many years.
Even so, the difference is imperceptible and in no way are the effort and time I spent worth it.
The only thing that cleaned somewhat satisfactorily is the bottom of the fireplace, which was hardly worn anyway since I use a grate with a tray underneath.

I bought it because of the reviews, I got fooled once again by the reviews. Unfortunately, I tried it three times with a lot of persistence and scrubbing but unfortunately it did nothing.

Very good cleaning for the fireplace.
Be careful with the fumes, it needs an open window when spraying and for a few hours afterwards

The product arrived loose in a box, without proper packaging leaking, surprising considering it's a corrosive chemical
The product left in the bottle works well though

I cleaned the fireplace bricks. In my case, it did a good job. By testing with Swaz in a ratio of 1:5 out of curiosity, I saw the exact same results. Therefore, next time I will use Swaz, which is much cheaper and can also be used for many other purposes!

It left me with positive impressions, as seen from the photos, it does a great job on years-old stains. I imagine that the result will be even better on fresher stains.

Truly the most useless thing I have ever used for the fireplace.. It is the second season that I bought it, I said to give it another chance (using chlorine and everything, I would have had better results) but in the end, the product seems evident from the first moment. I do not recommend it!!

Since my mom taught me how to use it, I haven't parted with it! It's really good, it just requires a lot of attention and its use should always be done wearing gloves! I use it for cleaning the kitchen (stove & oven) as well as for pots (the bottom part that comes into contact with the stove).