Hi JohnH, i would have thought it would be pristine out of the box too.
I would be maybe if it is that bad/dirty, gently rinsing it under luke warm water with maybe some diluted dishwashing stuff,let it air out to dry completely,or hit it at a distance with the hair dryer.
This link
http://www.samirkharusi.net/filters.html shows testing of various filters on M42.
I have the Astronomik UHC, that hardly gets used, so i can't really comment on its quality and performance.