Even though it’s obvious that such a practice exists, living with free bleeding in the “civilized” world (read: “taboo world” or “rigid culture world”) can be tricky. What is free menstruation you ask? Well, here’s an interesting read:
Do I have an opinion about the practice? No! But I do have an opinion about people who make a fuss out of this: oh yes!
It’s another person’s body and clothes. That person is allowed to do whatever they want as long as they are careful to not interfere with another’s property (and this covers hygiene too). So, as long as this is a private matter of the person, society cannot interfere. And just to be clear: if you see a blood stain between a woman’s legs and you don’t like it, look away. It’s not anybody’s right to dictate how other people dress or look.