Leave the cleaner (e.g., pure citric acid) to act for some time. Wet the affected areas with cleaning liquid (possibly soak a cloth or toilet paper with liquid) and leave for a few hours. After that, the dirt is often very easy to remove. As an alternative to citric acid, vinegar, vinegar essence or vinegar cleaner can be used. Foamed cleaners have the advantage of sticking to smooth and vertical surfaces longer than liquid cleaners. Foam can also be sprayed directly under the rim of the toilet rim. They can be used to reliably remove limescale, bacteria and germs.