Posted this on my LJ, but may as well post here too. Here's a quick walkthrough for the CS rank up quest.
Talk to Abquhbah, then to a Galka npc shopkeeper at K-10 in whitegate. Talk to Abquhbah again, then the Galka again.
Now head to Aydeewa. I went in the entrance at I-10 in Wajaom. Pick a Scourshroom from a Mushroom Patch in the large open room at J-8/J-9. The patch at the north end of that room gave me a Scourshroom key item.
Now you must plant the Scourshroom in another Mushroom Patch. I planted mine at E-7 on the same map. I planted it around 2:00 Darksday and sprouts formed by around 2:00 Firesday. I picked it at 4:00 Firesday and it gave me 1 sprout + 1 extra sprout (note these aren't items or key items).
Now go talk to Abquhbah again. He'll ask you if you want to clean the mace yet. I could clean it twice because I had 2 sprouts. The first cleaning didn't clean the rust, but the second cleaning did. At that point I ended the quest and got CS Wildcat Badge.
I'm not sure about all of this but that's what I did.