Howdy,
I don't really think that bare-bottoms are the nicest thing to do to your fish. After all, it's not considered nice to keep dogs in bare concrete rooms. A few pots with plants and rocks are nice, but I don't really see the problem you have with gravel. Maybe your gravel size was not optimal, maybe you dont have any Malaysian Trumpet Snails (Melanoides Tuberculata) in your tank. Don't worry, they won't bother you, you'll never see them, they live in the gravel/sand. They keep the substrate free of organic matter, and they aerate it doing so. No tank should be without them! Just introduve a few, and make sure to remove the big chunks of dirt from your gravel regularly. The snails will do the rest. I have sand, and I don't even have to vacuum. My filter & snails clean the tank for me.
HarleyK