Rather than actually clean the office, we felt it much better to just close the doorway off. Of course this does have the added benefit of making the space more private when we are trying to work.
I even managed to find the same shelf brackets as the magazine had (thanks Google image search). A slap of paint all round (including a grey accent wall), plus some high-rise, non-health and safety approved stair painting - bob's yer uncle, etc. etc.
The plastering was much better than when I had tried it previously - as long as the sun isn't shining at the right (wrong?) angle, it almost looks perfect - just don't run your hand over it. Floor tiles still look crap, but hey, what you going to do?