Apparently this only works because of a facebook bug. The code that @Gazan wrote is not working even for him. They are also speaking about this on a russian forum: https://zismo.biz/topic/970874-kak-sozdat-kartinkussylku-dlia-rassylki-v-dire/. Probably best just to use a cloaker like many of you said, thanks for the recommendations. I am no longer actively searching for this, which is why I'm only responding now