DON'T PANIC! All ferronium rods are vunerable to damp and wet. That is inherent in their nature. That is to say that they oxydise. Small rod's are a lot more vunerable than large ones. Keeping them dry alleviates the problem. If you leave them in a damp pocket, you will, eventually, destroy the rod. As you would a knife. A normal wetting won't affect them, provided they are dried afterwards.