I feel your pain! My hair is very porous and keeping moisture is something of a feat! Espcially the ends of my hair.
The SS DT does great for moisture! I've even have used it as a leave in (mind you I used a very small amount.) It has done the best, however I still have moisture leaving the ends of my hair.
After posting about this myself, it was suggested to use something that would act like a sealant. Coconut oil is great, but it can make my hair look stringy so I can't really use it unless I decide to straighten my hair, however SS also makes a butter that just a tiny scoop on my finger and rubbing my palms together lightly and scrunching it into the ends of my hair worked! I've been doing it ever since and I have moist ends all day long now!
So yeah thats something that you can look into is things that act as a sealant like the coconut oil or your butters. Just be careful, if your hair is like mine it.... mine can look stringy and wet easily if I use the wrong thing or too much.
OH! and I always do it while its wet. Nevet dry.