[@Halvtand]
Number of things. Its honestly (For those not prepared for it) a good counter for both ice and fire releases. Ice in that salt can lower the freezing point of water fairly nicely. Fire in that it runs the risk of making chlorine gas, which, spoilers, is pretty bad for the human body. (Does dick all against electricity though. if anything, can make that better) 
Right now im just trying to come up with a more diverse tool kit than just adding salt to water that isnt just columns of the stuff.