Hello gunsandroses, if you are talking about the dragontongues promoted on the site. I know of them, and they are quite easy to use, however, when you use these, you can be lured into false confidence.
If you can breathe fire with the dragontongue, in NO way does it makes you able to do so without.
The only thing you can learn by using implements like these is the feel of fire near your face. If the fire so close scares you too much to try a first time without these things, then please think carefully if you "really" want to learn how to breathe fire or not.
Whatever you chose, don't let things like this lure you into the false security as mentioned.
Fire Breathing is dangerous, the way I learned it was practice and patience and in retrospect, it went far too quick.
I always suggest that people who really want to learn how to breathe fire find themselves a nearby tutor. They know the drill, they know the risks. And whatever you do, never try it without a safety person.