In Sekiro Shadows Die Twice, you’ll find an Offering box next to Hanbei at the Dilapidated Temple. This item becomes useful at later stage of the game.
After killing the Divine Dragon, much of Ashina's surroundings and Ashina Castle will no longer be available which will kill some NPCs and block certain items, which you will find below.
It also seems that if you miss the opportunity to unlock the Hirata Estate (second) for the Purification end, the 2 Prayer Beads it contains can be purchased in the Offering Box.
Broken Horn of Gyobu cost you 2800 Yen
Iron Fortress (Yen 4500)
Phantom Kunai (Yen 4500)
Anti Air Death Blow combat art (Yen 2200)
Prayer Beads (Yen 2200)