I agree, no sealant, especially RTV. However, I have had occassion when a head gasket would not seal. I taped 600 grit sand paper to a piece of glass and gently surfaced the head in a circular motion. Removed the studs and did the same for the jug. On installation, I used spay on copper gasket (available at many fine auto parts stores), and this is the ONLY sealant I would ever use on a head gasket, but the preferred method is no sealant.
Good luck
Rick