re: "Killing" the grain on pine boards

I think that refers to a “washcoat” or using wood conditioner.On woods such as maple, cherry and pine I mix about 10% of my topcoat with lacquer thinner and spray on light uniform coat.Then a very light sanding or scuff, and I am ready to stain.The washcoat prohibits the stain from totally penetrating the wood and therefore will reduce if not completely stop the stain blotching on closed pore woods. Unfortunately this will reduce the grain clearity in the finished piece.
Hope this helps.