Quoting SpaceCowgirl:" Would he do better with flushable wet wipes?"
This. My step-daughter is over 4 and didn't know how to wipe her own butt at all. Didn't even try. So when she came to stay with us, I bought the Huggies toddler wipes for her and showed her how to do it. I pretty much just instructed her to wipe, fold, wipe, and then use a new wipe if the wipe isn't clean yet. I watched her twice and after that she was fine. No skidmarks or anything lol. Her mom was shocked when she went back home and could wipe her own butt lol.