I've been drying these down and generally looking after my two new Dovo straights, imagine my surprise when i spotted some rust forming around the tangs.
So far I have only had this happen to one of my straights, my gold dollar. I imagine it's because this is the only carbon steel razor in my collection but I could be wrong. I got rid of the rust as far as I can see anyway, by using some mineral oil on a q-tip. I now try real hard not to get that part of the razor wet at all and really try to dry it good with a towel after shaving.
I learned about rust with my Le Grelot that happens to be one of those razors that can't sit without an oil barrier for long without showing spots. I was flabergasted when it first happened to me (http://badgerandblade.com/vb/showthread.php?t=137340).
Since then, I never let water sit on the steel when I set it down, I thoroughly towel dry the blade and scales, I blow out the pivot pin and I apply a bit of mineral oil to the blade and pivot after every shave. Also, I leave my razor out on the counter in the air to dry off before putting it away. It may be overkill, but I haven't seen rust on any of my blades since.
Easiest way is to use a sponge like chimensch to clean off any excess lather. I only run it under hot water when im finished, making sure only the blade gets rinsed.
I then wipe it dry with a soft cloth and finish off with a few laps on linen.
I have virtually no spots on my thiers issard, being vintage it'll rust scary fast if you let it. I do have very tiny spots but they are hardly visible and serve as a reminder to me, to keep an eye on that blade.
Just use a modicum of common sense and you'll be perfectly fine.
Oiling wise i only need to once say every few shaves with some ballistol, just to be safe and every time i hone it gets treated and left to dry with some tuf glide.
I take good care of my straights, and have never had a problem with rust or pitting until my recent Dovo. I took equally good care of this razor, but it already has pitting near the spine. I have no idea how this happened.