The brass top of the Stolpersteine ​​oxidizes over time, causing them to discolor from brown to black. Stones that lie in a busy shopping street sometimes remain reasonably clean due to the polishing effect of walking feet. To remain visible and respectable, they should be cleaned at least once a year in other locations, but rather more often.

Demnig recommends using a copper polish such as Brasso for maintenance. To avoid staining the surrounding stones, this product should not be applied directly to the stone, but rather rubbed with a soft polishing cloth or cotton tea towel. It can be rubbed after a maximum of one minute of drying. If necessary, this should be repeated several times. Optionally, a toothbrush can be used to clean the inscriptions. After cleaning, the polish residue can be removed with water and a brush or washing-up brush. If the stones are very dirty, more intensive treatment may be required. A strong all-purpose cleaner (with ammonia) can be used for this with the help of a scouring pad. To remove limescale stains afterwards, undiluted cleaning vinegar is suitable. In this case it is recommended to use a kneeling pad to protect the knees. The stones can also be cleaned with a tent cloth polishing disc (on a drill) and pre-treatment paste and then treated with a wool polishing disc and gloss paste.