Hard to say what will work, as the harness of the water plays an important role. Nonetheless there are a few liquids you can try before doing polishing.
[video=youtube;SNPtBeyOlNA]https://www.youtube.com/watch?v=SNPtBeyOlNA[/video]
If you decide to go with the wheel acid route be very careful, I would wash the car again after application, to make sure any left over acid mixture is completely gone, and apply a coat of protection.