Hand disinfection is one of the mainstays of infectious disease prevention, especially at hospitals. However, not everyone sanitizes their hands when entering healthcare institutions. Since the Covid pandemic there have been efforts to use mobile service robots to make it easier for people to disinfect their hands. Even though these robots do provide a benefit, most of them are not actively pursuing interaction with people. We looked at how adding interaction capabilities benefits the robots’ performance. We compared a newly developed modular interactive mobile service robot, HanDiRob, with a mobile hand sanitizer robot which is less aware of and interactive with its environment. Our tests show that when the robot shows clear understanding of the presence of people and interacts with them, the hand sanitization compliance rate improves very significantly (more than 300%). However there is still much to do before rolling out interactive mobile robots on hospital corridors.