I read it is a practice these days to do this fecal "rub" for newborns as a way to compensate for the C-section lack of it. I do not know if it happens in Brazil. Another factor to consider.
I've never heard of moms doing fecal rubs, but I've heard of many that do vaginal "transplants". I work in a hospital and we get questions quite a bit, moms will often take moist, sterile gauze and conduct the transplant themselves (staff can't really be involved for liability issues).
I just saw it in some documentary, but do not remember where. I found these, which look like what I heard described. I believe it is the same you mention: