Karon,
I have copied the info. below from this website http://uuhsc.utah.edu/pated/handouts/handout.cfm?id=1693. It's very simple sounding but takes a lot of practice and self discipline to not cough the regular way. I'm working on it though. One of the main reasons, amongst many other health problems coughing causes, is incontinence. I really think that would be a bummer to have to deal with so I'm going to try to avoid it. Some of the young ladies on this site - in their late teens are already having pee problems. Good luck huffing! Age 4 I think is a great time to start. Do research and talk to your doctor though but my thinking is if she isn't producing with biological coughing then what harm could it cause in teaching her a new technique. Keep me posted through personal message if you don't mind.
Huff Coughing: Controlled Coughing Technique
Coughing is the natural way of removing foreign substances from the lungs. In Cystic Fibrosis there is an excess production of mucus, which must be removed to maintain open airways and allow you to move air in and out of your lungs effectively. Retained mucus contributes to the risk of infection. In addition, the mucus irritates nerve endings into the tracheobronchial tree and can cause frequent, involuntary coughing, causing fatigue. Ineffective coughing can also lead to airway compression, making it so you cannot clear or expel mucus. Huff cough is a gentle way of coughing, which attempts to accelerate airflow while keeping the glottis (throat) open. To conserve energy and oxygen, you must practice and master the method of controlled "Huff Cough".
When doing the Huff Cough, inhale slowly, using diaphragmatic breathing. Hold the breath for 3 seconds. Then do a forced exhalation with an open throat or glottis. Whisper the word "huff" as you cough, and keep your chin up. The huff is a forced maneuver but never violent. The length and force of the expiration can be altered to maximize airflow and minimize airway collapse. Huffing continued down to a low lung volume will help to mobilize and clear secretions in the peripheral airways. When secretions reach the larger airways they are cleared by a huff at high lung volume and quicker exhalation. An essential part of the controlled cough technique is the pause for breathing control after one or two huffs. This prevents any increase in airflow obstruction in patients with bronchospasm or airway collapse. When the mucus has reached the upper airway, cough to expel secretions.
Huff Cough In Brief
1. Inhale
2. Hold your breath
3. Initiate huff maneuver
4. Breathing control
5. Cough to expel
Control your cough ------------ don't let it control you!