What really made this work well is the 2 shoes used.
The outer shoe is a high-top canvas style shoe that we very light and really held the inner shoe snugly (especially considering it was a couple sizes too big) Another key was removing the insoles and using papertowl. I am considering using a light foam or something to secure the inner shoe permanently.
I don't know if I would try this with a non wedge heel or not, I bet it would have to be at least a chunky heel. But the wedge boot worked VERY well. Didn't feel a lot different that wearing the boots by themselves.