Sustained Inhalation is done by inhaling essential oils directly from the bottle with long, slow, deep breaths. Inhale thru the nose and exhale thru the mouth for several breathing cycles. Sustained inhalation is a very effective method for applying essential oils and the most common method used during classes.
You may inhale directly from a bottle of oil, or from a rollerball, or you may place a drop of oil on a cotton swab or cotton ball and inhale from there. The use of a nasal inhaler is even more effective, if you have access to one. Or you can roll up small pieces of a paper towel, apply a few drops of oil to the piece of paper towel, and insert it partially to the nostril.
Sustained Inhalation is one of the many methods of using essential oils.