Advice I was given on a social services "closed secure area" first aid course.
Anything will do to start clotting...first aid is just that, initial treatment to stop blood flow.
Even a hand can treat a bullet wound, if you firmly place it over the wound...it is all treatment.
You want to see me perform a laparoscopy on a choker with a biro pen...
We did the training, hoping to never have to use it...never did.