Oil
Okay Cinder, you take the two white swords. (Treasure taking is one thing the DM never just assumes you do.) They are nicely made. By the way, let's just split the difference, shall we? You were supposed to make two saves vs. poison. We'll just assume you made one, missed the other, and now you're down to 2 hp total.
There is no oil to be found anywhere. However, you do find a small hole at the top of the blacksmith's head, with some old organic residue around it. Hmm.