Cedar is often used in the sweat lodge ceremony. ... The smoke of burning cedar is said to attract the good spirits and eliminate negative energies.  
How to use: 
Burning herbs, or smudging, helps to clear away negative energy, thoughts, and feelings. Smudging is a powerful cleansing technique used in the the Native American tradition. The effectiveness is based on the theory that the smoke attaches itself to negative energy. As the smoke clears it takes the negative energy, releasing it into another space to be regenerated.
This is true both of a space, such as a home, and of a person. The smoke from the burning herbs helps to clear one's body's aura and protects against evil and negativity. Smudging helps change the energy when you are very angry, unwell, depressed, resentful, or have had a fight with closed one.