Since he said "silicone gasket" I bet he's talking about one of the new style gaskets like what's used on A518's. But that's just my guess.
As far as not using sealer on the pan, they make RTV specially designed for transmissions using ATF. The old stuff didn't seem to play well with ATF but the new stuff made for it works fine. Just a PITA the clean off if you ever take it back apart.
