Nearly two years later now, this has all been going very well and time for an update. Not long after my last post, I adjusted the cleaning routine as follows and have be doing it a long time:
First, I clean all small/medium size parts in the ultrasonic cleaner with hot PBW water (stir the PBW into solution). 6 minutes, rotating 180 degrees any piece with trapped air bubbles half way through (to change where the trapped air gaps sit in the piece). I reuse the leftover hot PBW water from the ultrasonic cleaner parts to clean any larger water pieces (which don't fit the ultrasonic cleaner). First, I plug the bottom end of the water piece (or pieces) after filling it with the leftover hot PBW solution. Then I add more of that solution into the top end of the water piece, minimizing trapped air gaps. Then I rest the water piece in the sink for a few minutes, followed by turning the water piece 180 degrees around and letting it sit for a few minutes more. I also like to run a bit of water over the piece to each time I let it sit to remove any PBW residue on the exterior surface.
Then shake/agitate the solution in the water piece, remove the plug, partially drain it, shake again and then drain the remaining solution. After that, I triple rinse with tap water, shaking again, then triple rinse with distilled water, shaking again. And you only need ~3 Oz of water per rinse. I'm still microwaving dry the large water pieces with interior chambers... 80% power on a new microwave for 3 minutes. And with that, everything is done and clean clean.
PBW is far superior to ISO in my experience. Highly recommended... ultrasonic cleaning too. And a wicked combo. It's easy and fast enough that I've been cleaning my glass and vape parts after every three days of vaping for nearly two years straight now.