Im sure coke works fine. Just as some water and a terry or other abrasive towel (yes, abrasive towel.. if that makes sense). I would think coke would make a bigger mess than it would remove due to all of the sugar.
Today I cleaned some windows COVERED in smoke residue. I used a terry towel with my glass cleaner to start (I didnt want to get my mfs too dirty lol) and then I followed that with the same glass cleaner and a mf. It worked perfectly. So I think in bad situations, change the cloth and not the chemical.