Black Marks at the Bottom of the Toilet: The Natural Tip to Eliminate Them Effortlessly.

Hence the benefit of letting the citric acid act overnight. This tip works for all types of toilets: wall-hung or floor-standing.

But also for all types of materials: porcelain, enameled ceramic or stainless steel.

Bonus tips
For descaling heavily scaled toilets, you can also count on soda crystals (Saint Marc or any other brand)… or Coke!

Surprising, but it works! The use of baking soda should be reserved for regular toilet maintenance.

But used alone, it is not powerful enough to clean very dirty toilets.