Try Baby vicks on the soles of his feet. We get coughs ALL the time alto from viruses. Vicks or baby vicks helps. Do it every chance you can and keep them off their feel til its soaked in bait if you can.
After 2/3 days you should really notice a difference.
If you have a burner, teatree oil helps the body to produce the good cells( white cells i think) to help fight the sickness

Sent from my Galaxy with the barefoot princess covering me in kisses, so please forgive the mistakes