Since the Covid-19 pandemic emerged, there has been a heavy focus on hand hygiene. In schools and kindergartens, this means that teachers and assistants use a lot of their time to help and supervise children during hand washing. This paper investigates whether children in schools can be enabled to perform a proper hand wash without supervision from adults by introducing a smart mirror approach, providing instructions and feedback. Two designs are tested by school children. An evaluation indicates that children are motivated by and find the concept engaging. Results show that a ubiquitous system like this enables children to perform proper hand washing independently.