I have always had a practice of washing my braid after a trip to get the saltwater off it. I did not know whether braid deteriorated after continuing exposure to saltwater but I always thought it was a good idea to strip the braid off and soak it in fresh water as well as to properly wash the spools. Washing a spool with the braid on will never get all the salt off the inside of the spool.
Anyway, I wrote to Western Filament, the producer of TF XP recently to inquire about this. Typical of American companies on the internet, terrific communication and response. In a nutshell, Western Filament advised the following:
TUF Line braided line is virtually impervious to salt water due to its' hydrophobic properties. We do not recommend or discourage the act of washing or rinsing the line after use in salt water. We have not found that salt water causes any degradation of the line. However the washing may be more necessary to remove the salt residue from the reel itself.
Thank you Western Filament.
I've found this to be a good practice. On some of my spools, there is a tiny bit of corrosion notwithstanding my caution so I do think this is a good practice. I've also found that washing the braid and adding line conditioner to it when respooling does improve its casting performance.
In anticipation of the question of how I actually do this, there is actually a kit I use for this. It is a bit of a pain to get as it requires a purchase from Japan and then another from the USA but it sure makes life easy.