Whiskering should already be done when you start. However, some pieces will require either knocking down, or burnishing additional whiskers before applying finish.
That being said, apply ferric nitrate till well saturated, allow to dry, apply heat to blush. This is a must, and how the chemical reaction works. If whiskering is necessary, now's the time. If you wish, apply additional stains to adjust tint now.
When surface is to your liking, apply a flooding coat of Chambers oil til it won't take any more, going over the open grain until the same. Wipe off the excess, till none remains on the surface. Let it dry, and repeat till you're happy with the results. Usually 3 to 4 times. Easy peasy. Beautiful, in the wood, low sheen finish.
Hope this helps.