Absolute Aromas Eucalyptus Essential Oils (10ml). The oil is steam distilled from the fresh or partly dried, long and narrow leaves of the tree.. How to use eucalyptus oil for cough?. Try adding 2 drops Eucalyptus, 1 drop Chamomile and 1 drop Lavender to a bowl of boiled water. Lean over the bowl with a towel covering your head and inhale the vapours for a few minutes.. Alternatively, blend the same oils in two teaspoons of Sweet Almond oil and massage into the chest and back.. Or try eucalyptus oil in the bath.