This article theorizes and historicizes soap, a medical “gift” distributed by the US military to villages and hamlets in South Vietnam, as a commodity and as an infrastructure in the American war in Vietnam. During the war, soap not only operated as a tool to clean those the US military deemed dirty and uncivilized but also brokered the ideological movement of empire from the nation-state to the occupied regions of the Vietnamese South. Wartime US humanitarianism proffered soap as a counterinsurgent weapon of soft power and as an infrastructural poetic that securitized US empire against the rising tide of communist insurgency. Reading against the hegemonic archival practices that venerate the gifting of soap as benevolent militarism, the article moves to examine the anarchic practice of South Vietnamese black marketeering, which redeployed soap as an illegal market commodity to intercept the movement of US empire and, as a practice that arose in response to wartime capitalism and militarization, allowed natives to command new social relations at the cost of disrupting the Republic of Vietnam’s flows of capital and the United States’ ongoing war campaign. As an informal, opaque, and yet thriving infrastructure of its own, the black market fostered insurgent survival strategies that repurposed military supplies and gifts as versatile commodities, allowing even soap to escape its original containment as a civilizing agent and giving it new uses and meanings.