I in my long CF career <img src="i/expressions/face-icon-small-wink.gif" border="0"> I've tried lots of cough syrups, but only one worked for me and it contains Guaifenesin. This substance is derived from a natural source and is basically an over the counter expectorant drug and is effective in the treatment of the thickened bronchial mucosa by thining mucus and lubricating the airway. And is also a mild painkiller.
It is also used by singers for its ability to promote secondary mucosal secretion in the respiratory system which is the thinner, lubricating mucus that occurs on the vocal folds naturally when they are healthy and well hydrated. So that could help you with the voice.
You can find this substance in Robitussin or Duratuss, either as a single ingredient or with other substances, usually with antitusives.
It is also used by singers for its ability to promote secondary mucosal secretion in the respiratory system which is the thinner, lubricating mucus that occurs on the vocal folds naturally when they are healthy and well hydrated. So that could help you with the voice.
You can find this substance in Robitussin or Duratuss, either as a single ingredient or with other substances, usually with antitusives.