How to help a 4-month-old with a red throat?! I drip 1-2 drops of pi…

How to help a 4-month-old with a red throat?! I drip 1-2 drops of pink medicine, give warm water, and feed frequently. (By the way, we're breastfeeding.) The doctor says to gargle or wipe the throat, but I'm afraid ? I can't seem to do it. I gave him chamomile tea, but he had diarrhea from it, so I stopped and there was no more diarrhea. Can you suggest any folk remedies?