Natural ways to expel phlegm

Any herbal recommendations to treat my baby's (7 month old) cough? We already consulted his pedia who gave us Ambroxol Expel. Pero it really pains me na everytime he'll take his meds talagang isinusuka nya at hirap na hirap syang ilabas. Any recommendations will be highly appreciated.. Thank you. #FTM#firstbaby #pleasehelp #advicepls #firsttimemom