Yeah, they work! If you have a synthetic carpeted floor such as nylon, that is one large mass of poor dielectric. Lifting all cables off that surface will sharpen the focus, so to speak -- should be quite noticeable if you have a revealing system. If you have hardwood floors, I personally wouldn't bother.
I believe any elevator should be a natural substance, ie wood, ceramic, etc. Mapleshade has a very simple design that works well enough and isn't too expensive, so give it a try and let us know!
