Yes.
When I had a 10G, the vaccume cleaner seemed to make things more messy than it did clean, but when it settled and the filter sucked it up.
(I'm sorry if this doesn't make much sense, but I'm tired and I'm typing with one hand)
Well it goes cloudy because the force of the water pumping through the little net actually just breaks up a lot of the poo - small enough to be pushed in finer particles through the net. That's my major gripe with these devices - what the point of just breaking down the poo and distributing it through the tank that's disgusting. I've tried it, so know how it works.
Sure it catches some of the poo, but a lot gets pumped right back in.
Thanks bloo after that comment on poo i think i will know longer buy a battery operated gravel vac, stick to the hand one which dosn't mess the tank up.