I think I remember a TSB on hubs that said a light oil with good stiction, in other words, it sticks where you put it. However, you must remember my age and the probability of senile dementia...

I'd think that if you had good seals (you did put rtv on the hub flange, right?) water intrusion should not be a problem unless you spent a LOT of time in the water so that the interior gas cooled and caused a pressure difference. That's another thing the grease pack would solve....

Not responsible for advice not taken...