I have thought about using Kukaku, along with many others such as Tier Harribel's Fraccion, Nanao, Orihime, and Riruka. The main reason is finances. It's true that I work a lot at my job, but there are times where I'm not able to purchase a commission or two. It's not because I don't have enough money, rather I have other priorities to tend to. The best examples is paying my internet bill, phone bill, insurance, and part of my rent. Whatever I have left, I usually save and if I have enough for a commission or two, I'll forward over my commissions to Rtenzo.
As for Loly and Menoly, I believe their underage, just maybe.