When I lived in more humid central Texas (in the Austin area), I stored most of my unused knives in zip-loc bags, making sure they were fully clean & dry before doing so. Didn't have to rely on oiling or waxing them, stored that way. I just made absolutely sure the blades were clean - I used Windex or isopropyl alcohol for that, leaving no oils or salts from my hands or any other contaminants on the blades. That's about 99% of the battle. Storing in clean, NEW zip-loc bags kept them pristine. Put it in the bag and roll it up around the knife to squeeze out most of the air, then seal it.
Even after having moved back to my original home territory in New Mexico (much, much drier here), many of those knives are still stored the same way. And still no worries about rust. And each time I take them out to handle them, I always wipe them down with Windex again, before putting them back in the bags.
Most issues I've noticed otherwise were in natural handle materials like wood or stag. Moving from humid Texas back to very dry New Mexico had some handles showing the effects of drying, either cracking (mostly the woods) or warping (some stag handle covers). Waxing them could help, but it's still not guaranteed, as it's so very, very dry where I live. Whichever is done, be it oiling or waxing, one really has to stay ahead of it.
