Salt is an element that is difficult, at the very least, to remove.
The bad thing about rinsing with fresh water is that chemicals are added to drinking water to make it fit for human consumption. This photo illustrates damage done in about 1 year from expose to salt water. These parts should both look like the one on the right. You can see how salt has destroyed the clip on the left side. This photo illustrates two reel seats, the one on the right being typical of the effect that salt has on these items.