Can the minimum amounts of "cotton wool" from the tampon that could remain in the vagina after it was removed be dangerous to health?

Fine fibers can be excreted along with the blood or in the process of self-cleansing the vagina, however, if this does not happen, it is not beneficial for health. Foreign bodies in the vagina, especially blood-soaked pieces of tampon can contribute to infection: https://www.gdziepolek.pl/opinie-i-pytania/33886/infectvagin-czy-pozostawiony-przez-ponad-miesiac-w-pochwie-tampon-mogl-spowodow A good quality tampon is unlikely to leave fibers or "cotton wool" in the vagina - it is worth trying different manufacturers. If you are stuck in the vagina of a small fragment of tampon, it is best not to put on another one, but to use a sanitary napkin - there is a chance that it will flow out together with menstrual blood, as well as possibly fibers. After the end of bleeding, however, it is worth going to the gynecologist if you do not know whether something is left in the vagina or not.