I find that whenever I have a cold sore on my lip if I apply some ice to the cold sore and then apply some aloe Vera to the cold sore the cold sore starts to go away within a few days.
You can also get rid of a cold sore in 2 to 3 day using Apple Cider Vinegar.
Dip a cotton swab in some Apple Cider Vinegar and apply it to the cold sore and keep applying Apple Cider Vinegar to the cold sore 2 to 3 times per day until it goes away.
Apple Cider Vinegar is antibacterial and can help kill off the virus causing the cold sore.