I have never used this type of oil pan gasket are they any good for sealing? Should I put a thin coat of silicone down on both surfaces or use it dry?

Dry. They work great.

In my experience, they are best used on pans that have a flat sealing surface, unlike the stock sheet metal pans with stiffening dimples.

The sealing ridges in the tray's perimeter don't line up well with the dimples.

Just my 2 cents,

Joe

On a stock pan it worked great for you?

I use it with a stock pan. It works good with some Hylamar on the pan side. I usually use Hylamar on most of my gaskets that I may have to remove at some point.