If you have a gym membership, your gym may have a sauna and/or steamroom. Mine has both, that's why I picked it (Russians gotta have our steamrooms). You sit there for a few mins and you sweat buckets. I don't believe in all that detox mumbo jumbo, but what I do know for a fact is that sweat is salty and I lose a lot of sweat as I sit there.

You can eat all the salt you want and just passively sitting in the sauna will get rid of it. It's not hard at all. When it gets too hot you can step out, catch a few breaths of normal air and go back in. Be sure to have a big water bottle with you.

This stuff is easy, it's not like exercise. I usually go to the gym to swim 20 laps, then soak in the hot tub, then steam room, then sauna. But you don't even have to do the hard swimming, you can simply soak in the hot stuff if you're just looking to cut sodium. I bring an ebook to read as I sit, or just read the newspapers provided in the sauna.