Hi I'm new to window cleaning and need a bit of help and advice. I done my first house yesterday and my microfibres cloths are covered in black marks from the rubbers when detailing. Is that normal? I washed the microfibres on a 40 wash but they won't come out. Is there anyway of getting the stains out or should I just get new ones. I dont wanna put black marks on peoples glass. Any help would be appreciated thanks