Gaskacinch will hold a gasket in place for easier assembly. Silicone will help seal the mating surfaces. "the right stuff" can outright replace a gasket, (but good luck removing the valve cover on your 53 willy's after gluing it on with that stuff.)
for an
oil pan I like to: glue the rail gaskets in place to the block with gaskacinch, put a small blob of silicone at the parting lines where the rubber end seals meet thoe rail gaskets, and then run a very small bead of silicone around the whole gasket before setting the pan on.
Some people like to glue their valve cover gaskets to their valve covers with a variety of adhesives. I don't, I prefer having studs which will keep the gaskets lined up just fine during valve cover reinstall. I hate scraping off glued on cork remnants.