Frankly doesn't sound like a best idea in world to me. I'm afraid if the rider looses the balance he may have troubles moving back to saddle with this thing sticking everywhere. It's better to get a safe horse if you are beginner, not an artificial aid (I'm referring to advertising).
At the omoksee I went to yesterday they had ribbon race. It's pretty much that they give you a ribbon, you run a loop around the arena and the fastest time wins. One of the moms decided it would be a good idea to tie the ribbon to the kids wrists.