At first they my look worse because they are trying to heal, but they will die and fall off. (gross, huh?)
You may have to have them treated several times. I have one spot that just wont stop. All the other places have never come back after the initial removal.
Also-it seems to me that the acid treatment works better(at least for me). It hurts more, but is more centralized, when they freeze them they just spray they stuff on and end up freezing more than just the wart!