The only product I have tried that actually works in removing black mould from showers. But ruined by the worst spray mechanism I have ever used - it packed up with most of the contents still remaining. To solve the problem, I have bought a cheap spray bottle, and that works far better. I find it staggering that a company, after the many complaints in the past about HG's spray mechanism, has still not got a decent spray mechanism. Despite that, I have had to give the product a 5 star rating because it actually works, but buy yourself a cheap spray bottle as well, to dispense it.