The answer to this question requires a little anatomy discussion. The vagina is basically a tube that leads up to the uterus (which is where period blood comes from). The uterus is closed off from the outside world by the cervix, which acts as kinda like a door. When you have a period, the uterus gets rid of blood and tissue through the cervix, which then goes to the vagina and out of your body. Menstrual products like tampons and menstrual cups go into the vagina, but nothing (except for an IUD) ever goes into the cervix. It’s a very tiny hole.

So to your question about cleaning out the vagina. You really shouldn’t have to. The old dark blood is likely actually coming from your uterus. If bleeding happens when you aren’t on your period, it could be a few things:

Spotting. This term usually describes some bleeding that comes from your uterus but isn’t enough to fill up a pad or tampon.

Breakthrough bleeding. This is bleeding that happens between periods but a pad or tampon is needed. This is most often associated with starting a new form of birth control.

An irregular period. If you’re having “a lot” of blood, clots or brown blood, this could just be an off-cycle period, and you may end up adjusting your schedule in the coming months.

My point is that blood does not hang out in the vagina after a period, so there’s no reason for a “clean out.” Your vagina should take care of that all by itself!