seawater

Is there some special way to wash seawater out of cloth? I know the ocean washes things clean metaphorically, but it makes them dirty and smelly and itchy in the mundane sense. I didn't think it would be a big deal, but my current washing machine is not impressively competent. I have detergent that's good at getting the smell of secondhand smoke out of my clothes, but it's not working for this. It's fine for the clothes I just wore at the beach, but the shirts I actually wore in the water still smell of the sea after 2 washes and there was even a tiny bit of odor transfer to other stuff that was in the washing machine. I had a good time at the beach, and the reminder was nice for a while, but it's getting to be annoying.

I know there's something you can add to the wash-water to get chlorine smell out of swimsuits. Is there something like that for seawater?