Brad, Container says: DAP Fast N Final - Lightweight Spackling. Just note that once you've painted & weathered the brick or stone wall, you absolutely have to seal it with clear, before applying the spackling. When you're packing the spackling into the mortar lines and then pulling off any excess, it will mix with the weathered colors on the wall if it's not sealed.
NO need to use the expensive Testors Dull coat any can of Flat Clear Coat by Krylon or Rustoleum will work fine and last alot longer than the Testor's cans. Same sealing requirement if you're going over a stone wall engraved out of pink insulation board and painted and weathered with acrylics.
