I have used them 3 times. First 2 times i was quite happy.

Most recent time, after buying 4 hours of cleaning, I really couldn't tell if they'd been or not when i came home from work. I think you need to be very specific on what you want them to do.

In our case the place was generally clean, I stupidly thought she would notice that and maybe find the bits which actually needed work, under things, behind things, above things, crevices.. Nope. I think just vacuumed the already clean floor and re-washed the already clean worktops etc.

Be specific, point to what you want done, then at least if it's not, you have something to complain about.