Ajwain oil is an excellent natural remedy for respiratory health. Its expectorant properties help clear mucus from the respiratory system, making it useful in treating coughs, colds, and even asthma. How to use for respiratory health: Add 3-4 drops of ajwan oil to a diffuser or vaporizer to inhale the soothing aroma. Alternatively, dilute the oil with a carrier oil and apply it to the chest or back to help relieve congestion. By promoting clearer airways, ajowan essential oil can help you breathe easier and reduce the symptoms of respiratory issues.