I used spray adhesive that you can get from Home Depot to hold the fabric to the 703. Then I used long toggles bolts and painted strips of wood to fasten to the wall. The strips of wood were 1/8" thick and 1" wide, about 1' long. Ran the toggle bolt through a hole in the center of the wood strip, then through the center of the fabric covered 703 then into a hole in the drywall. Tightened it down lightly. Works fine, lasts a long time and looks great. Got the fabric from Walmart for $1/yard. If you can easily blow through it, then it'll work good for acoustic treatment.
btw: I merged (or at least tried to merge) this thread with your other one. That's why it might be a little confusing. Please don't cross-post in the future. I might move it to the Studio Construction section where it really belongs.
Cheers,