I just got over a nasty cold. I'm glad I am feeling better, but at the tail end of the cold came a few (un)lovely coldsores. I have a simple trick that helps mine dry up faster than if I just let them go. I dab a little bit of rubbing alcohol on them with a q-tip several times a day. By doing so, it dries the sores out faster so they don't last as long. I wish there was a way to make them stay gone, but since they are caused by a virus, there isn't. The rubbing alcohol shortens the life of my coldsores down to a few days, rather than a week or two.
There are a few things to remember when treating your coldsores. The most important is to not pop the little blisters. Doing so will increase the chances of them spreading. The key is to get them to dry out, and not spread them further. When you start feeling that telltale tingle, start applying the rubbing alcohol to the area in question. I use the rubbing alcohol on mine at least 5 to 6 times a day. Since we can't make them stop coming, the goal is to make them go away as fast as possible. I have used prescriptions before for my coldsores, but honestly the rubbing alcohol works just as well, if not better for me. I can't guarantee that it will work that well for you, as I am not a medical doctor, but it's an idea to try out next time you get one of those nasty little nuisances.