Moisturized hair is soft, IMO.
Anyway, I will tell you what works for me when I wear my afro out: S Curl No-Drip Activator spray. After shampoo and conditioner, towel dry the hair and spray S Curl into your hand, rub palms together and apply. Hair should be moist and easy to comb. At night have him wear a cap to bed. But if that's not manly, then Saran wrap under a doo-rag. (I won't tell if he won't). Next day he will not need to apply S Curl again, but his hair will not only be soft and easy to comb, it will be shiny and very healthy looking. I will show you what a difference this simply regimen made to my Mom's hair when I get to a PC.
Oil makes my hair hard. Shea butter feels great on application but hardens my hair later. Creams feel good on application then not so great later. S Curl and Hawaiian Silky keep my hair moist and soft w/o making it sticky and I only need apply after a wash. They are the only products I use when I wear my hair out.