Cooking salt goes good with the fish on your plate. However, it doesn't have all the other trace elements included in synthetic sea salt mixes, which are required for healthy inhabitants.
I have used salt for brine shrimp but not for my aquarium hmm I am sure it would work but like emilyb says you would lose some other elements that are there for the fish as well as the coral reef.
I have one of those vacuum packer machines and I could smoke some steelhead or salmon in trade for ???? whatever you are smoking. I bought a 21 foot jet boat a few years back so I have to go fishing in it quite a bit. (To justify the expense we will have to talk business at least once of course!)