Fastbottoms- I'm not pushing Salt Away, I've just used it for years and seen first hand what the difference is between washing with fresh water and using SA. Your mechanic is entitled to his opinion, but I question if he has ever actually used any of the many salt neutralizing products on the market. My mechanic told me that Volvo Penta tried to buy the Salt Away company so they could use it in their engine flush systems. My experience is that the difference between a fresh water wash and using the SA is like night and day. There is ususally still some buildup of salt crystals with just fresh water unless you spend a long time at it. With the SA it's all gone. To each his own but if fresh water alone doesn't remove all the salt on a hull, then I would think it stands to reason that it won't remove it from inside the cooling system of an engine any better. Seems like cheap insurance to me. Also, these products are primarily sold and used for de-salting salt and sand spreaders where it is generally accepted as standard procedure by almost all municipal public works departments(I operate four snowplows as part of my business-we use SA on them, that is where I first heard of SA). But like I said, I'm not pushing it, just passing on my own personal observations.