Purification of metallic objects in the presence of a liquid and layer silicate(s)

Process for purification of metallic objects, comprising an oil-adsorbing step in which a composition containing:

• a liquid and
• a layer silicate component are applied to the metallic objects,
• wherein
• the process is performed in the absence of surfactants in the composition, and
• the layer silicate component and the liquid have a ratio of from 0.05:1 to 0.6:1, based on weight, and the composition has a pH of from 4 to 10.6, the process is performed at a temperature of from 10° C. to 50° C., or both the composition has a pH of from 4 to 10.6 and the process is performed at a temperature of from 10° C. to 50° C.