Thanks, all.
Splinter - The precolor (waterbased stain) gets down into the grain without much effort, but cross-grain motion with the pad pushes it further in. The video I referenced mentioned that the precolor doesn't cover the hard grain as well, and I found that to be true if I buffed too vigorously. The black oil/wax will find a home in those crevices and really help create an overall black finish.
Barb - Nice finish on the picture frame. That's just what I want to achieve on the chairs with the pronounced grain showing through.