This specification covers a terpene base solvent cleaner in the form of a liquid, which forms a transient emulsion with water. The cleaner has been used typically for the removal of residual soldering flux and polar and nonpolar contaminants from component populated circuit boards subsequent to soldering operations, but usage is not limited to such applications. The cleaner is used in in-line and batch cleaning systems with provisions for spray-under- immersion, ultrasonic immersion or immersion-spin cleaning, and with provisions for a water rinse.