Glad to say most brands are moving away from this system.
The problem was caused because you can't put a fine bb thread in carbon - so early carbon frames had a threaded alloy piece bonded into the frame to take a standard threaded bb...
But then racers wanted stiffer cranks, so larger bb axles, and lower q- factor than achievable with ht2, and...
Marketing guys wanted a lighter frame!
So don't bond in the ally threaded piece, just leave a hole!
This system was never meant to creak, so the solutions are varied, depending on cause, quality and materials - as you can see from this discussion.
We've tried and fixed many creaking bbs.
(But not all)
Following the manufacturers instructions and fitting a new bb is usually the first choice.
Sticking rather than lubing is 2nd, but whatever works is great, hopefully without compromising the material, although it's hard to see anything carbon with pf bb being a "bike for life"
But of course a shop doesn't want a non-standard repair to lead to future failure on a high end piece
There are a few brands where once a well-used frame is a couple of years old, and perhaps with a larger rider, it's very challenging. This leads us to believe there can be wear or distortion in the shell.
Cheap crap can creak from new.
There are a lot of clever solutions posted here, to allow a creaky bb sufferer a good chance of a solution.
We occasionally get riders with horrible creaky bbs say:
"Doesn't bother me at all"
The ultimate solution? - change our minds