This is not really what that is for and I do not recommend it. Elemental fire energy is very dangerous. Even as little as 10 breaths of it could possibly give you some extremely uncomfortable and possibly unsafe reaction. And this effect might come to you several hours later after you did the invocation. So doing multiple breaths because you think that you are not feeling it, this could be dangerous.
I recommend to try only 5 breaths of the element, and not any more. Then if you do not feel it, wait at least until the next day. Because you may feel all of this hit you all at once at a later time.