There's only one housing furnishing I can think of that can be purchased with Poetics (a portrait of a Heavensward NPC, purchase in Idyllshire).

There are several Orchestrion rolls that can be purchased with Poetics (Mor Dhona, Idyllshire, Rhalgr's Reach). Thanalan and Shroud Grade 3 topsoils can also be obtained with Poetics via a roundabout method in Idyllshire (buy Unidentifiable Ore for Thanalan, Unidentifiable Shell for Shroud then trade to a neighboring vendor for the topsoil).

Another option for Poetics is to buy gear to trade in at your Grand Company for seals to buy ventures, crafting materials and other items.