My ntm doctor told me that I could do all three, saline, aerobika and vest at the same time but I physically can not. I was doing the saline at the end because I thought the vest and aerobika would shake it loose and the saline would wash it out. However. my copd pulmonogist recently told me to do the saline first. Apparently, the saline liquifies the stuck sputum so that the aerobika and vest can shake it loose. My treatment takes about 45 minutes plus 5-10 minutes after to catch my breath. Then there is the clean up so it's over an hour twice a day. Sigh.
The saline is the most effective treatment to get the stuff out for me and if I were to have to shorten the time, I would leave out the aerobika and vest.