Many classroom protocols for extracting dna from cheek cells instruct students to swish a sports drink in their mouths as they scrape the inside of the cheek. why would it be better to use a sports drink instead of water

During extracting DNA from cheek, it is a classroom and standard protocols to students to used sports drink in their mouth as they scrape the inside cheek than water. The reason for this is the sports drink contains salt and concentration which is compatible with the cells inside the cheek. Additionally, another reason is sports drink prevent cells from damaging or breaking apart and releasing DNA before getting a sample.