I think they're just funny decoration, I doubt a bar that big could get away with dirty ones from the patrons.

As of last night, only 4 pairs had found their way above tha bar. If they had some new ones, wouldn't they have filled it up? I don't know.

I'm all for a bar have Ambiance. I'm just not for used or clean underwear hanging from the celling.
Does that mean I'm getting to old?