In the US "toot" is sometimes used to mean "fart" so I can see why that might not get wide adoption. (Though it might be regional, and definitely more of a word to use with kids)
Toot is one of those words where context matters. No one confuses "toot your horn" to have anything to do with farts. It's like the words black and the word white --they can refer to color perception (though technically not colors) and they can also convey other associations, a few positive a few negative but have no relationship to the color itself. So it is with "toot". Toot may be used as a polite word substitute for fart in a specific context, but generally does not mean fart.
Also see punctuational period and menstrual period. I haven’t heard of any native speakers confusing that given context.
Only in some places is fanny associated with the buttocks. In other places it's associated with vaginas --which do "fart" in a way, but not the same way and it's not called a fart anyway.
