Bird poop is funny stuff!
Water Won't do it, the cleaners won't do it but cleaners water will (I use IGP Pink). It's common sense really, Bird (and spider) poop has some fatty content and ammonia, urea etc which needs a polarity between cleaner and water.What I tend to do is wet the area, then squirt on some pink bit at a time with agitating with a brush. When you hit the right raito, the poop comes off.By the way its the same with puke and human poop (I use pink and water to clean the head.ThanksJim Willis