A method for strengthening an extruded catalyst honeycomb filter body, including: contacting an extruded catalyst honeycomb filter body and a siliceous formulation including at least one siliceous source comprising a silicone emulsion, a silica sol, or a combination thereof; drying the contacted filter body; and firing the dried contacted filter body to provide the filter body. Also disclosed are zeolite-based honeycomb filter articles, including a matrix of walls of: a primary phase material homogeneously distributed throughout the walls, as defined herein.