My worst toilet experience was in Western Australia in some little town. We went in, and there was a syringe dispenser,sink and trash can.On the door of the single toilet cubicle,there was some weird gang sign. I went inside, and it reeked. There were wet wipes soaked in -blam!- on the floor,-blam!- smeared on the walls, the toilet was backed up and the lid was cracked and dirty. There was a small flusher that did nothing. On the ground there was an old news paper and on the wall written in Permanent Marker was something like "Use this stuff". Instead, I had my buddies go down the street to get toilet paper. I sat their, positioning my self above the toilet to have the best dropping efficiently without any "splash damage" from hitting the seat.
So, flood, I am sure that this is not the worst and you probably have many other more disgusting stories, so share.