Well, good luck Simon, there's not a lot you can do unfortunately, especially if you have young children with toys everywhere..(Thankfully that's long in the past)
No, it's spend a few hours getting the place ship shape for viewers, only to be told they haven't even put their house up for sale yet, I actually physically threw one couple out of the front door once, after Mrs WR spent three hours tidying up, and nearly an hour showing them round....Grrrr
Never mind, it's all part of lifes rich tapestery....:-)
Good luck....