Sounds a little crazy but made my own.
Take a piece of 1/2 plywood, and an old pair of shoes, trace the outline of the shoe sole on the ply wood. Left and right. Cut the ply wood to the shape. Then take a handful of dry wall screws, and screw them through the ply wood. I used 1.5" screws, space them evenly about an inch apart.
Now put on your old shoes, hold the spikey plates to the bottom, and wrap the duct tape around to hold them on. The screws will go though the tape, be carefull how you tape, so you can take the shoes on and off. Worked for me