Well all I can say is when the flames are rapidly approaching your house the last thing on your worry list is the under growth growing back.
Having lived in Spain and France they will use any means to get control of the fire and extinguish it.
If as reported in LA they do not like using sea water as it hinders the recovery of the undergrowth really, I thought it was the undergrowth was the problem.
I have seen fires in Spain engulfing mountains and burning right down to the port area in Javea. There is a mountain there that looks like the head and trunk of an Elephant (Montgo) totally ablaze. Fire fighting aircraft dumped tons of sea water to put the fires out. Within 12 months the undergrowth and trees were recovering, must be different salt water in the Mediterranean than Paciffic salt water.
If salt water is so bad for growth of plants why is it that sea weed is used as fertiliser and has been for as long as I can remeber. Use it myself, straight off the beach and dig into my Veg patch. I even eat seed weed, it is just knowing what type to eat.