Introduction: Leaving the abdominal cavity open is a well-described and frequently utilized technique in the treatment of severe intra-abdominal sepsis. Irrigation through a negative pressure wound therapy device is a technique employed to assist in the closure of wounds as well as the reduction of bacterial contamination. Furthermore, hypochlorous acid has been found to be safe and effective in microorganismal elimination from extremity wounds. There is no literature regarding the infusion of hypochlorous solution into the abdominal cavity for intra-abdominal sepsis or mucopurulent abscesses or biofilm. Objectives: A 47-year-old man with granulomatosis polyangiitis was started on weekly rituximab. After 4 infusions, skin sloughing, ultimately diagnosed as toxic epidermal necrolysis, developed. During the hospital course, he developed sepsis and bowel perforation necessitating an exploratory laparotomy. The abdomen was left open with a temporary abdominal closure using the Abthera open abdomen negative wound therapy device; however, the abdomen remained infected with visually diffuse, thickening mucopurulence despite multiple washouts. Therefore, a VAC Vera-Flo irrigation device was combined with the Abthera open abdomen negative wound therapy device and cyclical irrigation of hypochlorous acid. After 72 hours, the purulence visually was improved and no adverse events were recorded with the placement of intra-abdominal hypochlorous acid. Conclusions: The combination of two medical devices for the intra-abdominal instillation of irrigation is considered "off-label use" from the manufacturer's recommendations. In addition, the repeated instillation of hypochlorous acid solution has not been described but was noted to have visually decreased the contaminated effluent within the intra-abdominal fluid.