This is all very useful to read about, i'd never heard of using carnuba or bees wax before, or even the silicone spray!
The way I understand how this works, is to first establish what it is that causes the steel to rust. I think in the surface finish of all steel, there are small and very fine imperfections in the molecules of the whole surface of the part, it is these "free" or loose openings in the close knit structure that allow the the free oxygen that's present all around us that we hardly pay attention to*, that slowly settles on the surface. Over time the oxygen begins to chemically react with the steel, and the rust begins to bloom like algae on water or lichen on stone! Rust in a way is a visible example of "oxidative stress" in action on a substance.
So when we apply these myriad of preventatives, which we've found work over the years, we are clogging these free gaps with another substance which doesn't have the same reaction with the iron, that oxygen does, and thus creates a barrier to stop the oxygen settling, because the imperfections have already been filled with something else!
Another analogy that seems to confirm this mental theory of mine is if you were to leave a roughly sawn hunk of steel next to a very finely polished and smoothed piece of steel and leave them outside on a fairly clear spell of weather. We would expect the rust to act far quicker in the roughly sawn piece, simply because there are even more imperfections to settle into than the polished piece. Although both would eventually rust of course without any further action.
I think I've got that right? Interesting fact is that iron should actually be a very common element in the earth but we find it relatively uncommon to find because of the way it reacts to oxygen. The core of the earth itself is made of iron, and hence that, and many other minerals are scattered all over its layers and surface.
Gold is an interesting one because it is so rare, and that it doesn't actually originate from this earth, the scientific consensus on the origin of gold at the moment is that it literally "fell to earth" and was seeded in someway, probably through space rock. So maybe the renaissance artists were onto something when they kept using gold colours to depict heaven? 
*You can speed this process up with water and moisture, which allows the oxygen to act even faster than in air, although there is moisture in the air as well.
Michael W
Edited By Michael Walters on 20/12/2016 11:48:21