The oil will protect the blade from further rusting, but make sure the blade is dry before applying it.

I towel dry my straights after use and then leave them open on a dresser away from the humidity of the bathroom for an hour or so to air dry before putting them away. That helps ensure they don’t get stored damp.

When I know a blade is being put away for longer than a few weeks, I apply some razor oil (camelia will also work) before storing it.

Some of members store their blades using desiccant packs to make sure there is no moisture around the blade while it’s put away.