I have found an easy way to apply the foam as it dissolves when it touches the heat of skin. I fill the cap with the foam. I part my hair with a comb. Then I use a paintbrush, dip it in the foam paint down the part and move on. When whole head is done I use fingers to rub it in, then wash hands very well. I have found that a watercolor brush size 10 round works best. It holds the foam that dissolves when it touches your scalp.