When I had a dwarf lion, I fed live like you did, and slowly weaned him off of it onto silversides. I would buy a pack of frozen silversides and thaw out a whole one, or half of one depending on size of the dwarf lion. Id hold it in the tank, and wiggle it around, or at least try to, like a normal fish would move. It took some getting used to for it, but eventually it warmed up to me and he started grabbing them.