Thanks for asking. Yes, I used the Remover as soon as it arrived and was astonished with the result. I have an Indian Sandstone patio which is four years old and, as so many others have found, developed black spots after the first three to four years. I tried bleach, biological washing powder, scrubbing brushes, pressure washer as well as patio cleaners from a garden centre. None of those made much impact apart from Dettol bathroom mould and mildew spray which has a high chlorine content. That did have some impact but not very satisfactory.
Your Patio Black Spot Remover, however, was amazing. By the time I’d reached the opposite end of the patio, the first side was already clear of black spots! I let it stand over night before rinsing, and the patio was left looking as-new. Such a relief.
Since then I’ve given the patio a good couple of coats of sealant and removed the tree which I think was responsible for introducing the black spot by leaf-fall. I’ve also recommended your product to the guy who designed and implemented my garden as he uses Indian Sandstone quite a lot in his designs.