Some of those properties are not safe to even walk in to. I was cleaning the windows on a flat in Ruislip a couple of weeks ago and a van pulls up behind mine. The van had something like "Hillingdon Contract Services" on the side.
A man gets out and says good morning, pulls out some keys and opens up the flat below the one I was cleaning. He went in but came out a minute later and said "Blimey mate come and have a look at this"
I went in, briefly, to have a look. The smell was vile, the whole flat was indescribably filthy and there were hundreds of empty rum bottles everywhere.
The flat wasn't even owned by the council, they own very few, but they were renting it. An alcoholic bloke had been living there and then had died. I don't know he had died in the flat or not.
Without going into details, apart from the fact that the bloke must have been living worse than a pig the effects of advanced alcoholism are incontinance and uncontrolable vomiting as your liver packs up. Enough said?
If you want to clean up those sort of places, fair enough because thats what you could be getting into.