I've used both and wax does help to make it slippery, but in my opinion the silicone spray is better. I use the spray over my entire "quilting" table, which is just cardboard boxes, taped together, then a couple of pieces of the heavy clear vinyl from JoAnn's, which is also taped, then spray lightly, wipe off and boy, does it make a huge difference.
I'm not in my sewing room right now, so I don't know the brand name, but you should be able to pick a can up at any fabric store.