I've never burnished or boned a stock. Perhaps it helps seal the grain as well, don't know. But - I do know it took 56 coats of oil to "Browning" finish a REALLY piece of Claro for a friend.
Sanding every 3 thin coats, then applying more, more sanding, more coats then once all of the pores were filled, three thin coats that were polished with an oiled rouge to a grande piano finish.
That's what he wanted. Maybe burnishing would have sped up that process or doing the sanding slurry of oil and wood to fill.
I used 1500 grit paper to take the finish back down to the wood between ever 3 coats.
That took a LOG time, one full day between coats to make sure the finish was hard.