If as I suspect all the wood faces are already varnished then that's one thing. You're looking for a cleaner of the salt off and then what?

If the varnish is weak or missing that's another thing. Which is it or a combo of both? Or what?

For getting the salt off, I'd use something like Dawn dishwashing soap, just a bit in fresh warm water, rinse and repeat as necessary.

If you want to treat a bare wood surface with something good for the wood it most likely would contain oil or some variation thereof as wood likes oils. I might investigate Daly's products like Daly's Benite for a wood treatment that helps to replenish the wood but also toughens the surface a bit when it dries.

A lot depends on what you got, what you want and it's hard to tell without photos and more details.