You have to make the punishment fit the kid, no doubt about that.
My cousin used to get an old-fashioned whipping from his dad about 2-3 times every week. As my uncle would walk away from administering the whipping, my cousin would be dancing a jig and making faces at his back (while maintaining a convincing level of sniffles to mask the behavior).
But make him sit inside on a sunny day and you could see the pure agony of it etched all over his face.
You have to go with what works.
A kid who uses abusive language and throws things at someone in a store clearly needs her discipline level ramped up in a big way! Of course, the parents will probably try to sue the store owner and then they'll have to feign surprise when the little gutter-snipe gets caught for her first juvenile felony.