I use the Prevident as toothe paste and brush well for about 2 minutes then I follow that up with my trays with GelKam (.4%). I leave the trays in for about 20 minutes every morning. The direction say 5 minutes then don't eat or drink anything for 20 minutes. I kind of just put them in and forget about them while I get ready for work. I hadn't heard of a foam for home use, but I'm going to ask about it.