James, whenever you get a house that disgustingly bad, (we all get them once in a blue moon)   after you are happy you 
 have gotten them as clean as you can, just start from the first window again to the last window checking there are no 
 dirty water runs coming from the vents, where necessary clean again  under the vents, be very careful this time to not
 get anymore water into the vents, as they could run again when you have long gone, hope you charged her well for this
 DIRTY FILTHY JOB.