Apple Cider Vinegar does work to get rid of cold sores due to it's antibacterial properties which can kill the cold sore virus.
To get rid of your cold sore using Apple Cider Vinegar soak a cotton ball in the Apple Cider Vinegar and apply it to the cold sore for around 5 to 10 minutes and do this twice per day until the cold sore goes away.
It worked for me and within 4 days the cold sore went away.
Toothpaste is another remedy for drying out a cold sore so you can try that too if you want but the Apple Cider Vinegar is what works best for me.