The word 管用 is formed by combining two characters whose core meanings create a vivid conceptual metaphor: 管 (guǎn), which originally means "to manage" or "to exercise control over" (as in a pipe that channels and controls flow), is paired with 用 (yòng), meaning "to use". Together, they evoke the image of something that, when put into use, can be effectively managed or controlled to achieve a desired outcome. This fusion yields the sense of something being "effective" or "serviceable", literally, something that "governs its use successfully" or "holds up in application".