I treat salt water runs a bit more aggressively than water but really both should be the same detail. I typically pull the drive shaft and hose it out with fresh water, same with rudder shaft and regrease with marine grade. The rest gets a fresh water rinse and a dry. Pretty much all that needs to be done with my sailies and scalies when they hit salt water.

I sail in the Chesapeake Bay (US) and it's tributaries, which I think is more brackish than salty in the part where I am.

It's a glass covered wooden hull, with a copper bottom, and any metal outside the hull is brass, copper, aluminum, or stainless. The boat first sailed in 2011 and I haven't done anything to it. The copper bottom has browned some, but I wanted that.

I oil what ought to be oiled, especially the stainless rods that hold the external ballast to the bottom, salt-water or not.

If you have ferrous metals on board, wiping them with machine oil or PTFE after a sortie is never a bad idea. Same goes for the stuffing box and other moving parts.