I think regardless that the oil and water is going to mix when operating. When sitting, the water will settle to the bottom, no matter what type of oil you use. Depending on how much water is in the drive, it will start to oxidize on the internals. I think your always going to get a little bit of moisture in with the lube. It's just the nature of these things. It will either come from condensation or a slight leak. I mean, anytime you have an engine part in the water, somehow it's going to find it's way into the mechanisms. Just watch when you drain. There is probably a tablespoon or so that will drain off then the lube. If you got more than that, then you got problems somewhere in the outdrive and will need fixing. No amount of emulsifiers will keep your internals from rusting.