Students in Bowling Green, Kentucky participated in a “handwashing challenge” Wednesday in celebration of National Handwashing Awareness Week, which takes place annually during the first week of December.

The challenge tasked the second grade students with applying glow-in-the-dark lotion to their hands, then putting those hands under a blacklight. The idea was that the lotion would symbolize germs.

Students walked from the black light to the sink where they washed their hands. Students whose hands displayed no more lotion after they were washed won the challenge.

One of the kids credited his decision to spend two minutes washing his hands for his test results, which he says showed that he “got most of them,” reports WBKO 13.

National Handwashing Awareness Week runs through Sunday. To learn more about the event, check out this recent report.