It depends on how much growth there is: with the samples I had, it only took about fifteen seconds for the thorn samples I had to stop their growth and fall apart. I tested several times on a few samples, and waited a day or two to make sure that it did not grow back after the thorns were exposed to the cure.

Once I determined that it worked and that it would be safe for consumption, I then gave the cure to the person that I had gotten the samples from to begin with, and we were able to observe the thorns not only cease their growth, but fall apart from where they had been wrapped around the person's arm after a few minutes. They haven't grown back since.