I've been in some stomach-churning hell holes over the years
One or two that come to mind were the ****holes where people filled envelopes for a living... and lived among dogs and their excrement, chain smokers, urine soaked sofas, places where you would gag.
The nasty end of the life-spectrum in conditions that beggar belief. I acually look back on it with some sadness, because when you are young and see these things it's easy to think they are 'below' you in some way, whether they are alchoholics or whatever, well in a way they are 'below', but the snobbery involved in looking at these scumbags is almost as disgusting.
Some humans lives are truly terrible and degrading, tank god I'm a crummy little window cleaner.