I'm not sure what residue you are referring to, since most companies use dawn dish soap and do not leave a residue. However, if you do have something on a window that your regular solution won't take off, I recommend using a few tablespoons of ammonia with your regular cleaning solution. The smell is awful, but it works great for outside windows, or construction clean-ups, where the customer will not be bothered by the odor.
For hard water stains (white spots that can form a thick residue), which are common on outside windows, especially ones that are hit by sprinklers, I recommend Ka-boom. Apply the Ka-boom, scrub with 0000 grade steel wool, then rinse, and you'll have brand new looking windows!