After my plumber recently repaired my toilet and something contemptuously looked at my range of soft toilet cleaners that might superficially ensure cleanliness, but unfortunately almost invisible places small limestone gave rise, I followed his advice and got me on the hard-hitting variant chosen. And I must say: Respect! You could tell when distributing the liquid, as it begins to foam at the calcium stains. The tip for good ventilation to ensure the room (is on the bottle), is justified and useful. After 2-3 hours I'll be gone off with a brush and a screwdriver for some stubborn parts at the rim - and the bathroom looks like new. Am thrilled.
