Sealant for Element Corrosion

I'm getting towards the final stages of my e-brewery build and I'm looking to protect my element against corrosion (rust it already showing after some tests using water).

I know there's a few threads already addressing most of this. The most popular methods seem to be using a silicone sealant or a sacrificial anode. I'm looking to try the sealant method with this:

http://www.bulkreefsupply.com/catal...ium-sealant/?gclid=COfv44TJkLUCFQ-e4Aod6HkA2A

Few questions:

What's the best way to apply this? Do I just cover the base after installing the hex nut or will it still leak through to the base? Should I apply some and then screw in the hex nut before it cures?

What's the best way to get off the current rust? Does vinegar work?

Any advice on this process would be extremely helpful to me.

Would this stuff be safe for the high temps? Interested in this thread as well myself now as last night I, too, realized there was some rust forming on my element after testing with water.

Based on other threads I've read here, it will be good up to 400 degrees.