The present disclosure relates generally to the field of medical devices and medical device accessories. In particular, the present disclosure relates to a tool or accessory for cleaning a medical device. For example, the tool or accessory may clean a fluid delivery lumen of an endoscopic submucosal dissection (ESD) knife. The tool or accessory may include a housing with a first portion of an elongate member secured within a first portion of the housing and a second portion of the elongate member extending into a chamber of the housing.