I wonder when the flushing thing came in.
I was reading something earlier describing the first public toilet sanitary towel bins - a enamelled box with a slot in the lid and a bottom that flipped open to allow it to be emptied easily by the attendant so they didnt have to touch the pads. This was the 1930's (1935 to be precise) and the last line says:
'The less scrupulous solve the difficulty by putting the napkin down the lavatory drain'.
So women were doing it even then and I'm guessing thats why sanitary bins were brought in in the first place.
FWIW I dont, not even the little pieces of paper backing. I managed to completely block my parents toilet drain by doing this in the mid 90's, never forgotten the cringing conversation about it I had with my father who had to clear it out.