A novel method for cleaning dental and medical instruments is disclosed, in which a cleaning solution including a low-residue corrosion inhibitor is used not only in a wash stage of the cleaning cycle, but also in at least one subsequent rinse cycle, to optimize both cleaning and rust prevention. A novel cleaning solution particularly suited to this method has a neutral to alkaline pH and comprises in aqueous solution a low-foaming surfactant and a corrosion inhibitor selected from the group of C4-C16 alkyl pyrrolidones and C1-C18 alkylamines.