Massage into chest, temples, forehead, cheekbones, nostrils & upper lip every 5-15 minutes at onset. Then apply as needed. Can also put 1/2 teaspoon in a humidifier or pot of hot water as a steam inhalant.
Applying more frequently at onset of symptoms - and leaving on overnight will produce effective results.
Concentrated Herbal Balm - a little goes a long way.