Has anyone ever used a product called Boeshield T-9. I have been using it with great success for a long time. It is marketed as a rust inhibitor and lubricant by Boeing Aircraft Company and can be found in marine supply stores.
The label says it "is a combination of solvents, lubricants and waxes designed for penetration, moisture displacement, lubrication and protection". Depending on how thick the application it "dries to a thin waxy film that clings to metal for months".
Boeshield T-9 has worked well for me compared to other products I have tried but I have not done any methodical comparison testing.