Upvote:2
I initially asked in a comment whether you were specifically asking, then realised it didn't matter. I'd found a New York Times article about hunting in Hawaii, but specifically on Oahu.
However, the hunter guide that they mention, Hook You Up Outfitters, has a page on hunting hogs (about half way down) and they indeed include hunting options on Oahu, the Big Island, and Kauai, so it looks like they may be a viable option for you on this and future trips.