We developed a closed-loop handwashing station that enables participants to wash their hands while engaging with sustainable water use practices at Material bar. The system integrates vernacular approaches to hand hygiene with experimental filtration techniques. The handwashing station consists of three main components: handwashing, a circular water loop, and a two-stage water filtration process. The sink itself begins the filtration, using gravel and sand to trap larger particles. Water then flows into a set of containers equipped with a pump that drives it into the second filtration stage. This second stage uses a transparent tube filled with zeolite absorbers. As part of the process, we experimented with 3D-printed zeolite. While this material is suitable for additive manufacturing, it becomes fragile after firing. To improve its performance, we used a differential growth pattern to increase the surface area for absorption.