These help rid the respiratory system of bacteria and mucus. Make a cup of lemon tea by grating 1 teaspoon lemon rind and adding it to 1 cup boiling water. Steep for 5 minutes. Or, you can boil a lemon wedge. Strain into a cup and drink. For a sore throat that comes from coughing, add 1 teaspoon lemon juice to 1 cup warm water and gargle. This helps bring up phlegm.