Alcohol rusts blades? I'm a noob. I used to get 3 shaves out of a Mach 3 cartridge. I reckoned the tap water I rinsed the blades with was evaporating and leaving a bunch of minerals and such on the blade, maybe even rust also.

I started storing the Mach 3 cartridge in a closed container full of rubbing alcohol when I got done shaving, and I would be able to use the cartridge for weeks.

I don't plan on doing that with my straight razor though, I read that a good strop session will hone the blade.