Fact: In many countries, a noose is considered a lethal weapon.
Do you really want to have a noose on your stage? What you can do in place of a real noose is to wrap one piece of rope around your 'noose', leaving enough at the bottom to make the loop - then, using a needle and thread, use one stitch to create the loop.
When I was taught this trick by a props master, he called it a "Stagemans Noose" (as opposed to a hangmans noose)
This ensures that if the noose ever gets caught on something, it will not entrap the wearers neck, and also only result in a slight bruise.
As for the hanging part, well I can only echo what others have said "DON'T!" - two reasons, a dummy and scrim look more realistic - the whole "short, sharp drop" as opposed to the "controlled lower and stop.", and the other - well it is a task that requires great skill and risk assessment.