When I brew, I heat up my remaining sparge water (always have a couple extra gallons) to around 180 and mix in Saniclean and run it through the Therminator and my tubing with no cooling. After that, I drain it and discard the first pint or so of the finished wort before I start filling the fermenter. That makes sure there's no bugs in it as my hot wort is cooled.
After all is said and done on brewday, as part of cleanup I rinse the Therminator of any wort left inside with plain old water and then once again sanitize it with Saniclean, drain well and cap it off so that it won't grow any fuglies inside in between brewing sessions.
At work we have a fiber optic microscope and once I took in the Therminator and looked deep inside it. No crud, no etching, clean as a whistle.
As for heating the Therminator in the oven, I've heard that you can do that, but not to take it over 350 dF and only heat soak it for an hour. That high a temp would certainly sterilize it very nicely without risking any damage.
I would ask Blichmann what they thought just to be sure.