One of my employees has only one arm, but we just tied an Unger pole onto the stub and stuck a squeegee on top, he manages really well.
He also has no legs from the knees down, but we put some stilts on him, they are the extendible type which saves us money with ladders. He can reach about 10.5ft High!
Because he is disabled we can park the van where others cant, which saves us money on parking etc