Yea, I wish we'd get a more detailed explanation of the accounting on this. For all I knew it was totally plausible that fairings would be destroyed by sea water, and it was also plausible there'd be no damage. The part that confuses me is why they would spend so much effort trying to catch them with Mr. Steven if they are in fact serviceable after a swim. Maybe the idea is that salt-water refurbishment-and-reuse saves a bit of money compared to expendable, but mid-air-catch would have saved more but turned out to be too difficult?

Developing the recovery process has given them the chance to examine multiple fairings after they landed in the ocean. I'm sure they took the opportunity to see what refurbishing them would take, and perhaps that's what informed this decision.

I think that is only an issue with hard to clean equipment, like engines.