In the right direction! Now, move that litter box to the front of the cage for good so you can take it out to clean without a hassel (much anyway). Put a cardboard box in back on it's side with no flaps and a nice soft bedding on bottom for bed. He'll prefer that cuz it's in back and leave the sleeping in litter box idea alone! Trick is, doing all this without him escaping (take a few sedatives yourself if you can!) Actually, pull out the box with a stick and clean it. then, put in his new bed, he'll spit and try to run out so keep the door as closed as possible. (hopefully I'm wrong). After he settles in new bed, put litter box in near door (same with food, as you know, you don't want to have to reach in too far!)
You know- I think when we read to them, they think we are talking to them, and since we can't think of things to say for an hour, reading works. before I knew anything about ferals, I had a litter of 3 that I read to (some James Henry book, boring as hell). Anyway, they got loose, I chased them and had no idea what I was doing (let alone that chasing is the worst thing you can do) point being, in the end, one hour of reading every night next to their cage, and sleeping next to them and talking (sorry but it's "scientifically" proven) baby talk, socialized them in 3 weeks!!! They were older feral kittens too!
Have you ever noticed when you're on the phone talking and then you hang up, the cats wake up and talk? Well, when I hang up, Scamp suddenly feels neglected and mews for attention. I read once somewhere (cat fancy?) that when we're on the phone, they think we are talking to them!
How is the eye contact going?
great job!!! You are being very professional! keep up the patience!