I don't know what your case is but I will tell you that some of these agencies that have cleaning maids, put a limit of houses that this people must clean a day, sometimes it's impossible to do. If it's someone private, that's another story.
My friend and I clean three houses , two of them bi-weekly and the other one weekly. We are very lucky, we do it as a side job , not for a living. The people that we clean for , are very happy because we can do a much better job than one person alone. It takes us an average of 1.5 hours to clean each house, and only one of the houses occupied during the week, the other two are summer and weekends homes.
We are very lucky and we know it, but the people that we clean for are also very grateful that we do not steal, geez, we have the keys for both of them and the one has a baby grand piano in the livingroom and a Harley Davidson in the garage.
The other one leaves his credit cards laying around!!