[Gremlin]

My window cleaner used both methods depending on the type of property.
He uses the traditional method on my bungalow and always does the PVC window frame and ledge.
I have washed mine with brush and hosepipe once but found the dust from the garden stuck before the water dried and it left marks.
I suppose a proper window cleaner man would have made a better job, that's why I employ one now.
He does inside if I ask and charges double of course.