they dont use salt per say. This is some sort of sodium liquid thing. It still is corrosive as heck but I think it's worse than salt and it sprays in places that the salt never gets into as easily
Yeh, there are many 'salts'. Crystal, spray, etc. They do a lot of pre-treating here. Liquid that drops in lines and dries. They sometime start doing side roads that won't get worn off quick a day or two ahead of an expected storm.