Personally I would try putting some décor in the tank. Yes, the FH will use it to hide. But that is normal for a small cichlid to do. Some dither fish like fast danios also might help him feel comfortable. In the wild (yes I know FH are not from the wild, but their parents are) they watch the activity of smaller schooling-type fish to warn them about predators. If the small fish you put in are not scared of you, the FH will learn that you are food, and not danger. Putting him alone in a bare tank may make him get used to you quicker, but the fish will be under stress until then, and in my experience stress can be the biggest factor to a fish doing well or not.