I use scrap cedar fencing. I don't get this fad of laying food on a piece of cedar on a bar b que. I like to cook salmon NW Indian style. Take a slab of salmon, like a big fillet or half a whole fish, secure to the fencing with a couple of roofing nails. Then slant the board over a low alder fire. Two boards can be leaned together like an A-frame, or board can be secured with rocks. Nothing like it.
A new 6 foot fence picket can be had for between $1-3 at the home improvement store.