Desalination sprays and salt brine removers are not worth the money for an automotive application. Depending on the formula, they move in one of two ways. Acidic or (almost) neutral PH. Many are just vinegar and water. Salt/calcium chloride/magnesium chloride brine usually falls on the alkaline (basic) side. The school of why is to throw acid vinegar in salt. It neutralizes. I don’t know about you, but I’m not into washing off corrosive alkaline salts with corrosive acid. The other collection of removers are nothing more than a solution of sodium bicarbonate (baking soda) and water. School of why it neutralizes salts. The 32 oz sprayer is $15. 1 gallon jug $60+. Of course, anyone can find vinegar and baking soda at the grocery store for pennies. If you make your solution, it won’t cause cancer in laboratory rats in California. 
Dish soap has strong surfactants. Surfactants are “water-wet”. They break the surface tension in the water so it’s actually liquid enough to wash things off. They are also slightly alkaline, but not the oxidizer that salts are. You get the benefit of washing off salt, dirt, grease and having a fresh lemon smelling engine when the mechanic needs to dig something out. Something Something, dawn dish soap is safe to pour on baby ducks.
