Tea tree oil can help with some inflammation of the mucous membranes, which contributes to the pain of a sore throat, but most importantly it can help fight off an infection. If caught in time, it can also possibly prevent it from really taking hold in the first place.
Put 1 drop of tea tree oil into a glass of warm water, swish it around and gargle with it at least once a day. Don’t panic if you swallow a little bit, but try to spit out most of it. You can also add 2 teaspoons of salt which, thanks to osmosis, will draw excess water out of the mucous membranes that can create pressure and add to discomfort.