It's pretty common not to finish necks, as there are some woods like bubinga, padouk, canary etc. that are quoted as not needing a finish. But bodies are susceptible to a lot of different sorts of damage and I would not recommend a totally unprotected body even if it was made from one of these naturally waxy "no-finish required" woods. Black Korina is NOT one of those woods anyway. It is quite open grained and would deteriorate quite quickly without some form of protection. It is a very easy wood to get a nice finish on however. It responds well to various wipe on finishes. I have found Danish oil very effective and user friendly. The 'Telemaster' guitar in my avatar was finished by just wiping on danish oil with a cloth and rubbing it into the wood with 400grit wet/dry sandpaper a few times. After a few coats of that I waxed it with good quality carnauba wax and it looks terrific.