Buy enough sandalwood from a Gossipy Perfumier
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Sandalwood is expensive in this sort of quantity. However, if your pockets are full this might be the easiest way.
Game Instructions: You can obtain Scrap of Incendiary Gossip by using other Rumours items in your inventory.
Unlocked with 8 x Scrap of Incendiary Gossip
The scent of secrets
The Gossipy Perfumier never works with money, but keeps reams of notes on his clientele and other notables. You provide enough information to satisfy him, and he parts with enough sandalwood to make a substantial cudgel.