Cedar is known to be one of The Four Sacred Medicines that can be used for smudging a room. Cedar is known to purify a home by allowing unwanted spirits to leave and to protect a person, home or thing from negative energy. The smoke of cedar is known to attract good spirits.
The shell to put the bundle out is SOLD SEPARATELY
How to smudge: light the end of the bundle on fire until it starts to smoke. Allow yourself to have an intention to cleanse your room or home. Make sure to place something underneath (like your shell) in case embers fall off. Slowly walk around your room or home making sure you get the corners. You can say a prayer, tell unwanted energy to leave and energy made for your highest greatest good to come into the space. You can call on your guides, angels, god etc to help you bring energy of love and light into your space. It's a good idea to open a window or door to allow the unwanted energy to leave and also to have some of the smoke go out. You don't need a lot of smoke if you are just cleansing yourself or your room. Same goes for cleansing yourself. Just all the smoke to go down your arms, legs and head.
*the above description is not proven to help ailments or solve any problem. This is information that has been learned through mentors and other great websites.