Thanks Sailor, Eric.
That's pretty reassuring. My wife and I have both tried a little with no ill effects. I'll keep eating it in increasing amounts since it seems unlikely that there should be any problems. Perhaps I'll just pass it off as a Swiss.
As to the salt, the added wash water was only about 0.2%, and that is less than 50% of the whey, so I suppose it is not a surprise that it wouldn't knock out the Clostridium spores.