Describe a memory you have of a movie you saw a long time ago that you now can’t figure out what it was or it’s title

cant rernernber any

  This was before the internet existed and even before cable TV existed.  There were just a few channels on television, they were the big three broadcast networks, ABC, CBS and NBC, there was public television, PBS, and there were a couple of local stations.  No channel stayed on 24 hours a day, but late night and/or on the weekends, there were "All-Night Movies" on the local channels. The movies they showed were mostly old ones from the 1930s, 1940s, 1950s, 1960s, B-movies, etc.  Not technically all night, because channels would sign off at the end of their programming day, usually in the wee hours of the morning, and then they would sign on again around five am or six am.

  Ok, that's the set-up.  Another type of fare they showed late night every now and then was foreign movies.  The one I saw was in the French language, I don't know if it was from France or from another French-speaking country.  I can't remember whether or not it was dubbed into English or subtitled in English.  It was black and white, and I believe it had been made in about the 1960s.  It took place in either an girls' orphanage or a girls' boarding school.  Life there was extremely strict and regimented, with the faculty exacting harsh routine on the teen-aged wards.  There was a scene in which the girls were to shower before going to bed for the evening, they had to line up and march single-file from the dormitory to the washroom.  They were dressed in nightgowns or slips, and being watched over by the female administrators.  They marched into the shower area, did not disrobe, and each girl had to wash the back of the girl in front of her.  On signal, they all turned around and each reciprocated in washing the front of the girl in front of her.  Nothing graphic was shown, but the idea was there.  I don't remember much else about the movie.  Does anyone recognize it?