Couple o' things. First off, sea transport is way more than damp. Anything that is designed to protect metal in an unsealed containier has got to be good. I don't know if that's the company's actual claim, but it's worth investigating, at least.
Second, never, EVER put a gun in a plastic bag, a plastic case, or wrap it in plastic. Anything that doesn't breathe freely is the root of all evil. You will collect way more condensation inside a sealed plastic container than you will collect by wrapping it in a cotton towel. Only grease, or serious dessication will protect a gun inside a plastic container. No breathable nylon or cotton case has ever failed me, but a plastic one just about ate a shotgun. VCI bags are a good solution to the problem. They're a plastic bag that is impregnated with some chemical concoction that inhibits rust.
Third, cosmoline or something like it. CLP Collector is designed to keep a firearm preserved, but ready to fire, and is designed for, allegedly, five years of protection. The "ready to fire" makes me question its effectiveness. Strike-Hold may work, but I'm not sure how well it will do in an environment in which the temperature changes frequently. I don't know *that* much about it. I do, however, know that a good cosmoline-type grease, if properly applied, will keep a weapon in like-new condition pretty much forever. You want to coat all metal surfaces with it (take the gun apart and grease it down good), and then wrap it in something that will keep direct water exposure from occuring. Almost any quality commercially available gun case will do. You will want to wrap the greased-up gun in an old towel to keep from greasing up the inside of the case. Do try to keep the grease off of wood surfaces, as it tends to discolor them. You might take off the wood furniture and store it separately.
If you're really worried about it rusting, and I would be in a wet basement, grease is, in my opinion, the only way to go. It'll be a PITA to clean out, but it's as close as you'll get to a sure bet.
