The ideal method of doing this is by using a Cherry Picker like the USAF, I have no argument with that as it meets the requirement of removing the risk of falling completely and all flying station's should have a sizable pool of them with the budget to maintain them (it would make my life so much easier as I have been involved in WaH for 21 years and the only place I ever work where WaH tasks were painless was were the IPT removed all climbing facility's, purchased a cherry picker and provided a full life maintenance contract). The downside is that they are expensive, somewhat unreliable and in some cases unusable for a task as there is no safe method of work that allows you to leave the platform if the structure you are working on does not allow access.
A question for the EngO's out there, is WaH covered in any depth in stage 1 training, The reason I ask that is on a few occasions I've had JEngO's who have been totally clueless on the subject.
Nutlose
The rescue equipment basically is a rope (in a bag) and a trained rescuer and all they have to do is get the faller to a position where he is no longer suspended. The picture doesn't tell the full story as there should be two people up there with one of them rescue trained (not the guy with the brush). Should the guy with the brush fall, the rescuer attaches the rope to the aircraft at the same point that the faller is attached to, throws the bag out so it doesn't hit victim which will result in the rope hanging beside the faller. The rescuer then abseils down, connects the faller to his harness, releases the faller from his fall arrester and lowers him to the ground. There should be a person in charge at ground level who is also the rescue co-ordinator (in this case with a management radio) who will activate any medical response. The other option is they may have some form of device available that can be rapidly moved to the height that the faller to get him down (like the cherry picker that 99 Sqn does have for de icing aircraft (pity it isn't a lot bigger!!!)).
