Ed's lack of knowledge regarding the place he found himself didn't come out of actual lacking knowledge but rather disbelief. Yes, he did know which house he was supposed to be in but… Why did it look this way?
'Sharog's house was never this messy in the past' Ed thought looking at the messy clothes and garbage strewn about. The fact that Sharog could have such a varied mess was a testament to the progress that Sanctuary had made.
'The fact that clothing is being developed is likely due to the influence of the cavern and the lizardmen' There were many bugs there that could provide clothing materials.
As for the garbage, it was primarily organic. There were no plastics in the dungeon or the outside world that could be used as far as Ed knew. This organic garbage took the form of food leftover and and primarily there were Alchemical materials.
