Typical bleaching gels are too thick to penetrate rapidly into the tiny spaces around enamel rods. This is why you spend hours applying any typical bleaching product. In fact, in many ways this very long contact time is also the major reason for tooth sensitivity that results from the procedure.
On the other hand, the formula used in Power Swabs® is made of an extremely thin liquid that is thickened with air and foam. Therefore, as the foam collapses back into a thin liquid, it penetrates very rapidly into enamel. There is no need for trays or strips to hold the product in place. All that is needed is that you or your patients apply Power Swabs® onto teeth for about 30 seconds per arch just before any traditional bleaching product is applied.