I do the empty scabbard thing ever since I got turned away the first time I came with an actual sword. Better to do a scabbard with integral belts rather than a generic swordbelt with a scabbard tied or snapped on like I used to do. An empty scabbard, especially one of the cheap Windlass ones will hang funny w/out the weight of a sword. An scabbard with integral belts will hang at the same angle with or w/out a sword (or the difference is small enough to not matter). I wouldn't bring my DBK out mind you- could get damaged if I sat on it by accident so I use the Robin Hood one I got from MRL. Thick, sturdy and if it gets damaged who cares (well I'd care a little lol).
Last Sunday, had one of the gate guys run up to me because he wasn't sure if I had a sword in my scabbard or not (left the sword in the trunk). I still think they went a little overboard with that rule, sort of like the zero tolerance rule in schools.