@kathyjjb Glad to hear you tried the percussion and that you think it helped. Good news.
I know that when I started my BE therapy/routine all I was doing at that time was the percussion on my front...and I cleared the plugs after awhile. I had been sleeping on my back prior to learning about sleeping on the wedge on the left side. So in my mind the mucus formed the plugs in the upper area in my upper lobe(s) due to sleeping on my back. All that was before learning that is a no, no,...for all of us....to sleep on our back. Who knew!
After clearing the upper lobe area(s).... plug(s) began accumulating in my lower lobe, left side.
I started to do my fist percussion on my back a good while after starting therapy and did add the postural drainage after learning about the plugging being worse in the lower left lobe(s).
I think I removed the plug(s) that had formed in my lower left lobe because I brought up a good size plug a month ago. It actually looked like one attached to another.
When I asked the pulmonologists if sleeping on the wedge on my left side could be contributing to the accumulation in the left lower lobe.....they said possibly.
I know you mentioned, if remember correctly you can't do postural drainage???

However for your information or for others. For my postural drainage I use the high end of the wedge pillow with a bed pillow on top of it to allow for my hip area to be higher than my trunk area and my head is therefore low. I lay on an incline and invert myself. I lay on my right side then left side then my back and do the percussion with my hands on my front and fists on my back depending how I am lying for the postural drainage. I also do autogenic breathing while I do this. I do what I would call five sets, first the hammer, (See below) then inversion postural drainage, then I sit up do autogenic drainage and huff cough, walk and use the massage hammer and then go back to repeat all....therefore about five sets of doing this.

Also, I am going to mention what I also bought to help me with percussion on my back. It is called ..... Massage Hammer, Meridians Back Knock Massager, Double Head Back Scratcher Percussion Massager, Manual Massage Hammer. It is on Amazon for about $10.00.
I am fortunate that I can use it and it is not too much for me. I use it on my back. I like that we can control the amount of 'pressure/pounding' because the pressure/pounding is regulated by our own handling of it.

Do you take really deep breaths when you breathe in the saline to get it deep into the lungs? I know they say to just do your normal breathing but I prefer the deep comfortable breaths. When you breath out do you breath out as if you are blowing on a whistle to allow for the checks to not inflate but rather somewhat deflate.

It appears you are going to master it and get it moving ....to get it out.
Barbara