Jeff, read a few threads about scrubbers before you get started, if you haven't already. There's a lot of little tweaks that I wish I would have done with my first scrubber design. IME now, I am going to build my next one in a plastic tote or aquarium to keep the salt spray to an absolute minimum.
It couldn't hurt to try it, like you said. With enough lighting and flow over the screen - it will pull some stuff out of your tank. BUT, it's not the be all end all of filtration either. I am going to have both a scrubber and a skimmer on my new setup.