Cleaning solutions which, in addition to an acid (hydrochloric acid or sulphuric acid, phosphoric acid only before painting), contain an inhibitor (anion-active or non-ionic) wetting and dispersing agent and partly organic solvents as well as complexing agents and inorganic salts (e.g. silicates). They can be used to pickle and degrease simultaneously in a single operation, saving not only baths but also working time. The fats and oils adhering to the workpieces are often converted to alkenes (formerly olefins) and other wetting agents. The additives are added to the acid in quantities of 4-15%, whereby sulphuric acid is used 3-15% diluted, hydrochloric acid 1:1 diluted. The additives themselves are also known as pickling degreasers.