I have a problem. I suffer from a ridiculously excessive amount of canker sores. There is no cause nor cure, says my doctor. What does he know? I hate it. They last for about a week and always come in a pack, ready to conquer my mouth for the best and most inconvenient places. I discovered this week however, that there is an instant reliever! My new best friend, Pepsi when cold and carbonated does the trick better than anything I have tried. I don't know what this says about this product for normal use, but for my personal purposes, I have found my hero! It numbs my woes and makes my verbal life bearable for yet another hour. I love you, Pepsi.