Generally, we use the Aerobika or Acapella 1-2x a day. It seems no sputum or small amounts daily (I’m in no sputum group) are allowed to do it once daily. People who are bringing up sputum, need to get the sputum out since it’s a breeding ground for infections. They do it twice a day, every day.
We usually do it after nebulizer albuterol and/or hypertonic saline.
The video mentioned by McSwane has great info.