Tadh,
how would you clean cladding with pads ?
you could use 10" or 14" wide melamine mop pads, pre spray the cladding from the bottom to the top with your cleaning solution and allow to dwell, then just scrub the surface with a damp melamine mop pad and watch the ingrained soils just loosen away very easily, you can even rinse them off with just a hose connected to an outside tap, this method needs to be used working from access equipment that will reach your required heights, using a compressed melamine pad attached to the proper mop handle (this depends on if you are using 10" or 14" pads) will give more effective results when deep cleaning vinyl cladded surfaces than using a 2500psi hot pressure washer. Tadgh