1) Poisons, Drugs ect, would never keep anyone unconscious for an hour, not even a level 1 commoner. Because they are all "(save ends)."

2) The point is that in 3.5, you literally couldn't imprison a character of a high enough level without some sort of permanent anti-magic field (which there is no way to do in the rules.) Not to mention that you could build a character that could literally break a 5ft wall in 3 seconds with no items.

Add in the practicality of people not all being high level, and so it makes no sense for most cities to put that much work into a prison, and you had no way for most prisons to be anything more then symbolic when it came to PCs.

However, in 4E a level 6 Commoner could actually go ahead and imprison forever any level 30 character that consents to wait inside a small room for a couple hours "for the king to see you." Since you could then Magic Circle the room.

So you could have level 30 character trapped for all eternity inside circles, just waiting for someone to come along and destroy the roof above the circle so that it can rain so that they can escape the circle.