"I think I will leave my RSK on the beach when I am on saltwater"

I'd encourage you to take it with you. A 1 oz bottle of Militec is available on-line for just $7.90 including shipping from http://www.militec-1.com/ . That should last you a good long time (use it sparingly).

The most important thing to do is to thoroughly rinse the knife in clean fresh water as soon as reasonably possible to remove the salt. If available I'd use the hotest water your hand can comfortably tolerate to facilitate disolving any dried salts. The lubrication is somewhat secondary, so long as you lubricate it before frequent use.

That knife is just too good to leave behind!!!