OK...here's something interesting I heard from a certified Honda shop last weekend: "If flushing your motor makes you feel better then keep doing it. Flushing does not prevent corrosion (except maybe in cases where you are running in water with lots of grit.)" His feeling was that if the motor is designed to run in saltwater, corrosion would not be caused by saltwater but by some internal damage, and that flushing after running in salt water would not prevent further damage. He suggested that closely monitoring fuel efficiency was a better indicator of wear in your motor.

I specifically asked him about the muffs vs. the internal hose attachment and that's the response I got.

Personally, I will continue flushing my motor and washing down the boat and trailer thoroughly with fresh water because it does make me feel better!

Just thought you all would find this response from the shop interesting.