The most common way to use cascara is to repel negative energy and to put a protective shield around you and your space. You can do that by sprinkling cascara around the perimeter of your house, on your windowsills, put it in floor wash, around the bottom of your doorways or anywhere in your house that there is an opening to the outside. If it's your own sacredness you are trying to protect, you can take a ritualistic bath with the powder. It's just eggshell, so unless you're allergic to eggs or eggshells, you shouldn't have any problems. You can also add honey or salt to the bath for added magical purification, protection and sweetness of energy.