Intended User: Most anyone, indoors or out.  
Advantage:  Very Cheap and Easy, Hits you back
Disadvantage:  May not be strong enough to really wack at, especially with an axe!

Courtesy of Pete Kautz @ www.alliancemartialarts.com
Full Link located here

Parts List: 
1- 1" diameter or so x 4' long stick.

1 - 1" diameter or so x 3' long stick.

About 10' rope or thick string

Well as you see in the above picture, tie the 2 stick together in the shape of a cross.  Then with the extra hand it from the roof, a tree, a ceiling fan and get to work.