Just got a quote from a vendor down the street to clean and passivate my vacuum chamber and all conflat fittings: ~$225.00
Currently I would describe my chamber as filthy. Passivating it would restore all vacuum parts to a factory new condition.
Would my ceramic feedthroughs and glass viewports be damaged by the strong acids used in the passivation process? I’m guessing so.
Prometheus Fusion Perfection 
Passivisation of stainless is usually done with nitric acid, this will not damage glass, and shouldn’t damage most ceramics.
However, if there is some some cleaning step that involves soaking in any fluoride containing solution, a step sometimes referred to as pickling, one needs to watch out.
Find out what steps are involved and what chemicals are being used.
DV8
I spoke with Insulator Seal, the possible problem is acid attacking the brazing alloy between the steel and ceramic.
That’s not a ‘possible problem’, that is something that will happen for sure if there is exposed brazing anywhere on the parts.
You might consider a hydrogen clean in a vacuum furnace, if you can find a place to do it. not only will everything be cleaned, but the parts will be degassed as well, by the end of the cycle.
DV8