Gentlemen;
Some time in the late 50s or early 60s (here in Calif) the boat gang was selling 'flush attachments' that connected a garden hose to the water pump and washed the salts out, after ocean cruises.
I'm told that's "standard equipment" from the Mfg. today.
Most boats here are used for water sports at the Colorado River or one or more of our man made lakes etc.
Have fun-be safe.
