I wash/rinse the boat thoroughly with fresh water at the slip after each trip, even if only a daysail, and biweekly, at least, while it's in the slip. There's a lot of grime here in Southern California if slipped near the big cites (e.g., Long Beach, Los Angeles, San Diego). Around Ventura and Channel Islands harbors there's sand, dust, and bird poop, etc. Salt corrodes, leaves deposits, and can set up galvanic potentials on the metals, etc., that can cause electrolysis. I rinse every metal part of the boat that can be reached with the hose sprayer while trying to spare my neighbors water splotch on their own dirty boats! If it's been a particularly salty trip, I'll also thoroughly rinse the mainsail plus lower the (roller-furled) jib for a rinse as well. I've seen others do everything listed above but brush scrub with soap every stanchion, rail, cleat, winch, etc., along with all of the deck, canvas, and topsides after every trip, no matter how short!
