Water neck seal: Silicone or gasket, or both

[D-Day]

Well, due to a rusty and pitted water neck, I replaced it with a chrome aftermarket one near two months ago, picked up a new gasket, and replaced it and yadda yadda. Well, even though it was cranked down tighter than snot (though not too tight due to aluminum Edelbrock manifold), it leaked ever so slightly; through the gasket. Apparently I forgot to use some kind of sealant with the gasket.

So, I have a new gasket and some water neck silicone seal, and the question is, can I use both, or should I just use the silicone? This leak is really annoying.