Mine wouldn't stay put on carpet, so I finally put some hook velcro on the back. Mission Accomplished!
Perhaps put some loop velcro on your floor, and then the hook velcro on the foot pedal?
Yes, it means sticking it to the floor, but if/when you don't want it there, it will peel off and you can remove any of the gooey-residue with GooGone.
The waffle weave stuff ... skeptical about n it. Never tried it for sewing machine foot pedals, but doesn't seem to keep other things stable for me.