I doubt if you would need the pliers on the waste canvas if you are only cross stitching through the cotton top. I would bet that you couldn't stitch tight enough to make it difficult. Now if you were going to cross stitch through the sandwich, you've got a kettle of fish of a different sort with the back having knots and such.
Michaels carries the waste canvas. I've used it. I really think your easier bet is to make Label Block, I think it will make your life easier.
:D