Are you in a high humidity area? I live only 400m from the beach and the air is very salty and corrosive. Like my NZ mate Grazor above I carefully dry my razors with tissue, I then oil them (IKEA Skydd mineral oil) and store them in Plano tackle boxes that so far have kept them very dry and rust free. I found a Boker the other day that I had forgotten to oil, say about 6 months ago, and it was completely rust free. I think the key thing is getting them dry to begin with and then keeping the moist corrosive air away. You might also want to consider using a dessicant like silica gel or calcium chloride.