Dirty Money?
I'm with the others regarding the reason for the "go-around" but cleaning behind the airbrakes/spoilers and flaps is not a trivial task. Come to that, even cleaning the outside of an aircraft is not as straight forward as you might imagine. The first problem is safe access. You are a long way up on an A380 and even on the wings of say a 737, it's still to far to fall. The next problem is stopping water and cleaning solutions going where you don't want them. The sealing of ports, inlets, outlets etc. has to be done very carefully and a great deal of supervision and double checking is required. Lastly, if you want to clean behind spoilers and flaps, they have to deployed and then made inoperative otherwise the cleaners will be jeopardy should that device move when they are nearby. And then we have the time element. A proper clean may take longer than a day and in that time the aircraft might have earned you £250,000 or more.
PM