We had a call from someone in Canada some months ago who was buying an 8 bedroom country house with all the usual trimmings.
The job fell through in the end because he wanted it all doing between the time he took possession of the keys and the furniture removals arriving early afternoon.
I can work quick when I need to but not a complete 8 bedroom property in 4 hours or less, and without seeing the property first. We did get a floor plan from the estate agent and that was enough to say this would take longer than 4 hours on a good day, never mind having no idea of stains etc and people getting in the way all the time.