Blade that has the most rust-resistance.

I leave all my stuff in the bathroom...razors on the rack & some blades on the counter top, a ton of other blades stored in their factory packaging (with the exception of a baggie containing SE blades) under the lavatory. I run the vent fan while shaving/showering, but never run the water so hot as to steam up the place. I have *never* seen a speck of rust, either on stainless or carbon blades, even when left in a razor. Maybe it's because I dry everything off thoroughly when I'm finished. And it's average in humidity (77% as we speak) in the Hill Country.

Now...I may have to change all this once I move back to the Coastal Prairie in a few years, where the humidity hovers around 90% sometimes. I'll cross that bridge when I get to it.

 

I totally get it, I'm on the fence about whether or not leaving a used blade in my razor makes a difference.
I received my wife's grandfather's Gillette Black Beauty a year or so, he passed away 25 years ago so the razor had been sitting in a drawer in the bathroom, in the razor was a used blade, I saw no trace of rust or staining.

 

Dude. You already go through more work than any other person I have seen, on any number of forums, with your shave kits. I would think popping a blade out would be the simplest thing you do in your shave routine.

 

When I first started DE shaving, I would apply mineral oil to each blade as I loaded it into the razor. I was careful not to "wipe" the blade as every blade today has a protective coating; but I would "dab" the oil onto the blade. For some reason, that gave me a measure of comfort that I was taking care of my blade and getting the most out of my gear. I long since stopped that practice and I have not noticed a difference. I usually have two or three razors which I rotate for 3-4 shaves per blade. So typical modern blades last about 2 weeks in a razor at my house without much protection.

You can judge what your time is worth. If you want, you can protect a $0.12 blade with mineral oil so that it lasts longer than two weeks. For some of us, the economics does not make sense. This is not a criticism of folks who do spend the extra time. I imagine when I retire I will spend endless hours polishing razors, but at the moment I have other urgent matters in my life that require more attention.