I am not exactly the guy who have been doing that year by year, but I have some thoughts about cleaning and packing the gear after a high altitude expedition. I think some of it can be applied to your scenario.
- I would first soap-wash (if recommended) the gear so that there is no dirt. Dirt, deposited and remained there over the longer period time can cause the moving parts to malfunction/jam and catch rust.
- Then I would consider wiping it dry off from any moisture so that no corrosion will occur by condensation on a surface that could be colder than the ambient environment. The key is not to pack them right away. Once washed, dried off, you can still keep them warm by wrapping them into some cloth that absorbs moisture, e.g. a Turkish Towel.
- Oiling them is optional I'd suggest. If you know that you are going to box them up neat so that no dust can get onto it, oil them. If its likely that those will eventually catch dust, don't oil them. You can just drop a couple of drops to the moving joints though, so as to keep them intact, just in case. People like me who live along the sea, should consider oiling since the degree of Adsorption increases with Relative Humidity. Needless to say, costal regions are more humid.
And, what I do is, I regularly take them out, like once a month or so, cloth them a bit and pack them again.