@discographer-- Ice cubes are a great idea! Thanks for the tip.
Something I do is gargle with warm salt water. It burns, but it helps the blister go away faster. Salt kills the virus and dries out the blister so that it does not fill with salt. It directly skips to the scabbing stage. Gargle with warm salt water two or three times a day every day until the blister disappears.
I've also heard of people using toothpaste on cold sores before. So I suppose brushing your teeth my help but the mint in the toothpaste may burn too.