The best way to get rid of germs in a classroom is to make sure they don't fester in the first place. The best way to prevent this is to teach good hand washing practices. To get them properly clean and germ free, hands should be washed for at least 20 seconds with plain old soap and water. Teach young children to sing Happy Birthday twice so they'll know when the job is finished. And when there isn't soap and water available, hand sanitizer is a good backup, so keep a bottle of that in the classroom at all times.