A medical instrument cleaning concentrate and method for cleaning medical equipment. The method includes contacting the equipment with a cleaning concentrate dissolved in water. The cleaning concentrate contains (i) a biofilm permeation agent, (ii) a nonionic alkoxylated alcohol surfactant having an HLB ranging from about 5 to less than 8, wherein a weight ratio of (i) to (ii) in the cleaning concentrate based on 100 wt. % active ingredients ranges from about 0.5:1 to about 1.5:1, and (iii) and an inert diluents. After contacting the equipment with the cleaning concentrate dissolved in water, the contacted surfaces are rinsed to substantially remove detectible traces of the ingredients of the cleaning concentrate from the surfaces.