Starwax .

This extra-strong Starwax toilet descaler in powder form effectively works on the side walls and floors of heavily calcified toilet bowls. It is compatible with a septic tank and should be used on average twice a week. Instructions for use: Remove toilet stones. Flush the toilet to moisten the bowl. Shake the container well before opening. Sprinkle on the walls and bottom of the bowl. Let it sit for half an hour to overnight (depending on the thickness of the limescale). Clean with a toilet brush and flush. Use only for the intended purpose. Not suitable for chemical or macerating toilets. Do not mix with bleach. Avoid contact with acid-sensitive materials and do not use contrary to manufacturer’s instructions.