Rosemary for Help with Asthma?

Someone told me rosemary was a good herb to help with asthma and other breathing problems. I have COPD (chronic obstructive pulmonary disorder) and I was wondering how you would use it. Make a tea or what? Any information on this would be helpful.

Thomas Bartram, in "Bartram's Encyclopedia of Herbal Medicine" (available at Richters) lists rosemary essential oil for use as a chest rub to relieve congestion in asthma. Mix 6 drops of rosemary essential oil in 2 teaspoons of almond oil, and massage upper chest.