DO NOT USE TAMPONS OR DIAPERS TO CONTROL HEMORRHAGE.
Neither actually controls the bleeding, they just absorb blood that could otherwise be contained in the body with an actual dressing. Tampons in particular shed particles and are associated with vastly increased chances of sepsis. If you’re building an aid kit, get some actual woven gauze and some actual pressure bandages.
The tampons thing is one of the worst urban legends in trauma.
I specifically noted they can be used to absorb blood, similar to gauze pads externally.
in the case of more than just a scrape or cut direct pressure, hemostatic agents, pressure points, or possibly a tourniquet, is needed to actually stop bleeding.
Edit - although I will agree that either diapers or tampons are low on the list on things I would want to use to soak up external bleeding. Sure they will work, but there are much better tools for the job.