Parts-washing method

A parts-washing method comprising:

• a) contacting a part with an aqueous liquid cleaning composition in a contact zone at a temperature of less than 45 degrees C., wherein the aqueous liquid cleaning composition comprises at least one alkoxylate surfactant and is not heated prior to contact with the part in the contact zone, wherein the at least one alkoxylate surfactant comprises an ethoxylated non-ionic surfactant prepared by a reaction of an ethylene oxide with a monohydroxy alkanol or an alkylphenol, wherein the monohydroxy alkanol or the alkylphenol each having 2 to 20 carbon atoms, and wherein a total amount of the at least one alkoxylate surfactant in the aqueous liquid cleaning composition is 1 weight % to 20 weight % based on a total weight of the aqueous liquid cleaning composition;
• b) passing at least part of the aqueous liquid cleaning composition from the contact zone to a separation housing;
• c) separating the aqueous liquid cleaning composition by allowing it to settle only under gravity in the separation housing to form a separated aqueous liquid cleaning composition having an upper oily phase, an intermediate aqueous phase and a lower particulate phase;
• and
• d) withdrawing at least a portion of the intermediate aqueous phase from the separated aqueous liquid cleaning composition in the separation housing, wherein the at least a portion of the intermediate aqueous phase is for use as the aqueous liquid cleaning composition in the contact zone.