At the beginning of Chapter 13 (Orphan's Cradle), right beside the Save Point, you will see two packs of Sacrifices on your right and left. You will be farming the pack of four on your left since they seem to be closer to each other and easier to hit with Ruinaga, however if your characters aren't powerful enough, you can farm the pack on your right. Bear in mind that YOU CAN ONLY USE THIS METHOD BEFORE DEFEATING THE FINAL BOSS:


Set Lightning as Leader with Vanille & Fang as members. You will only need two Paradigms, which are Exploitation (COM/SAB/SAB) and Aggression (COM/RAV/COM). Set Exploitation as your default:


Engage in a battle with the pack of four Sacrifices. Scoring a Preemptive Strike is crucial, you must hit them with a Preemptive Strike or the fight will take too long. Getting a Preemptive Strike on them is quite easy, wait until all four of them turn their backs on you and then engage:



After the battle begins, have Lightning spam Ruinaga at the center of the pack. Ruinaga is the only ability you will need to use, don't use anything else. Wait until Vanille & Fang apply 7 or more Debuffs then shift your Paradigm to Aggression and keep spamming Ruinaga until you win the battle:




The battle should take about a minute to win. The common drop is "Perfume" which sells for 12,500 Gil while the rare drop is "Scarletite" that can be sold for 7,000 Gil. Keep in mind that since getting Perfume drops is preferred, you should equip Collector Catalog if you still have it. However, if you have upgraded it to Connoisseur Catalog and don't have any normal one, you should still equip it because it Scarletite drops tend to be more in number than Perfume drops (in other words, while you normally can get 1-2 perfumes, it's possible to get 3-4 Scarletite instead):


You can respawn the Sacrifice pack by either saving & reloading or moving down the pathway to their side a little bit (until they re-appear as red dots on the mini-map):