Just in case it's not clear: Speaking involves pushing air past your vocal chords. You can't _not_ speak without doing that, so you're already doing it. Breathing is a bit more complex, of course, which is where those notions of breathing exercises and techniques come from. In stuttering, some have taken it to be the case that the way we breathe influences our stutter. Whether or not changing the way we breathe can help with our stutter is an open question, and you won't know before you try (and also, if no proper controls are in place, nobody will know what's really going on anyway). The best thing to do is to work with a professional who can take a closer look at your particular case, and see if there are things you could try to improve your stuttering conditions over time.