It hurts because the gums are pulled, and some of the tooth roots are exposed to air. And if you don’t floss, those exposed roots can get infected. If this sounds familiar, a Waterflosser might be right for you. A Waterflosser is a device that can clean your teeth with cold or warm water just as well as a toothbrush and floss, but it requires no effort on your part. If you have gums that are prone to bleeding or receding, a Waterflosser is a good idea.