We all know the reason of putting the mezuzah on a slant to minhag ashkenaz is based on the Rema 289:6 the madakdikim are yotei both opinions ...
I have heard more than once that the mezuzah is placed on a slant as to let the kedusha flow into the room. I was wondering if there is any credence to this statement, I have never found it written in any sefer. Does any one know if this is a reliable statement or not?
Side note, if affixing mezuzahs for a sefaradi (who follows the sefardi minhagim) if the mezuzahs were previously affixed in a slant, should I advise them to switch to straight up or leave it how it is?
I found a Teshuva from the Maharil in his Shu"t siman 94 he brings from the Yerusahlmi, that the mezuzah needs to see the face of the room, therefore he explains that it should be facing on a slant in the direction of the room.