I use single double-edge razor blades. You can still buy packs of them in some stores.
I’ve been shaking the water off of the blade for years by banging the end of my old safety razor against my palm. Corrosion takes place more readily on wet blades. I get one to two months good usage out of each blade.
Around a year ago, I found a box of old razors and blades left by the former owner of this house. There were several old double edge razors and most of them had adjustable blade angles.
Just for the heck of it, I tried one and to my surprise it did just fine. It is not quite as smooth as the newer multiple blade razors but not that much different either. The only time I use it is when I let my beard go for a few days and then it actually works better.