A cleaning, disinfection, and indicator agent comprising a water-soluble permanganate, particularly for mixture with an agent for ensuring an alkaline milieu having a pH value of at least 11, which, in addition to the water-soluble permanganate, contains a further oxidizing agent, whose oxidation potential is above that of manganese VII to manganese VI, pH buffer substances, preferably primary and/or secondary alkali carbonates such as sodium carbonate and/or sodium hydrogen carbonate, as well as oxidation-resistant polyphosphates. Furthermore, methods for cleaning, disinfecting, and monitoring the cleanliness of commercial and industrial plants or plant components and the use of an agent according to the present invention as an indicator solution for ascertaining the cleanliness of commercial and industrial plants or plant components by ascertaining the intensity of the light emitted in the violet wavelength range by the solution are described.
