Saw some homemade chux with open tubes.
Quiet dangerous, if you would hit yourself

What you need:
>tube, caps (for leg of chairs - gardenfurniture; available in a home-improvement market)
>and cord - Traditional Tying - check the other tuts, if needed.
The main idea of my "tutorial" is to protect the open tubes with a cap > have a look at the picture
The picture on the left shows, what you need and the pictures (middle & right) show what you get.
I got some Chuks, but these below are my favos now.

peace
Irv