Hi
Sean, it does depend on how filthy it is but as a guideline:
For an empty property in not too bad condition (dusty or grubby)
Each bedroom 1/2 an hour (inc windows, door)
Bathroom around an hour (inc tiles, shower screen, floor)
Landing/hall about 1/2 an hour to an hour(depending on size)
Lounge 1/2 to an hour (again size matters)
Kitchen 2-3 hours (depends on how greasy minging it is)
Add an extra hour or 2 for unknown, unseen problems i.e. can get the oven clean, scraping the windows, mopping floors (laminate) skirting is stained heavily. If the property is minging double all times.
These times don't include carpet cleaning.
Regards
Martin