Just rinse it with fresh water.

Yes, that simple. Shake off the sand first, then hose it down or dunk it in a bucket of fresh water. Let it air dry completely before storing.

Salt is water-soluble, so a fresh water rinse gets rid of it. Sand falls out when dry or washes off easily. No soap needed unless there’s a stain, and even then just a mild dish soap and gentle scrub.

The real trick is drying it fully. Fold it damp and you’ll get mildew. Pop it open in the sun for an hour or hang it over a railing.

Don’t overthink this one.