I don't know if it does what it promises,
but I didn't see any crazy difference.
Maybe it's for some other specific use ....

It really disappears!!! Accumulated salts on the tiles, yellowness from the water running from the pots, light rust, and every trace of dirt. It cleans and does not alter the joints of the tiles. I used it on the floor of the terrace which is made of beige-brown twig. The terrace became new!!! and not just like new!!!

Two photos are from the terrible condition of my floors before using it. The tile is ceramic porous, the worst thing. Wet the floor and put the product in a bucket, use a hard brush for carpets and scrub (it requires some work) tile by tile, leaving it to act for about five minutes. Rinse with plenty of water using a hose.
My balconies became new. I bought it because I saw good reviews.
Great value for money purchase!

Influenced by the positive comments, I decided to give it a try.
The test field was initially the tiles of the outdoor terrace. The tiles were installed in 2010. Despite regular cleaning, they had turned yellow from dust.
Applying this specific cleaning product, one initially sees it creating a white foam where it falls (definitely not something we want on our hands - so: gloves) and emitting a strong smell (not unpleasant but it's better to wear a mask, especially in closed spaces).
Personally, I let the liquid work and used a hard brush for additional cleaning, but in reality, the liquid did all the work on its own. The brush helps spread the liquid over a larger surface.
Then rinse with a pressure washer as much as the surface we want to clean can withstand.
The tiles became "almost like new".

(Photos will follow soon)

I did not expect this result. My balcony had been poorly done, resulting in water pooling on the opposite side of the drain and leaving stubborn stains that couldn't be removed even after a year of using chlorine and endless scrubbing. I used this product and with just one application and a little scrubbing with a broom, it didn't make it look brand new, but I am 100% satisfied because I had seen the comments and thought they were exaggerated based on their price and the terrible condition my balcony was in before. Unfortunately, I don't have a before photo because I also didn't expect such a result.

I used it on the marbles on my balcony. Although outdoors, the smell was very strong, so it would be good to wear a mask for the fumes. The surface started to "froth" and the foam turned black. The result was amazing.

Very good cleaner for surfaces such as the old mosaic on the balcony and bathtub with stains.

It cleans deeply tiles and grout. You pour it on the surface and it produces black foam because it removes anything useless that has stuck on the tile. It is good to have a hard brush to scrub the grout a little with pressure. Be careful not to inhale too much because it feels like it burns you.