Re: There are special toilets...
"IIRC In "Fear of Flying" (1973) Erica Jong made the comment that when travelling in Germany there was a pervasive smell - owing to the toilet design and the use of pig manure on fields."
That book is not for the squeamish. Jong seemed to be fascinated by bodily function smells. It's instructive, in the way that a maintenance manual for a marine toilet is instructive but with added descriptions of sex.