A method for applying a surface treatment to a plugged honeycomb body comprising porous wall includes: atomizing particles of an inorganic material into liquid-particulate-binder droplets comprised of a liquid vehicle, a binder material, and the particles; evaporating substantially all of the liquid vehicle from the droplets to form agglomerates comprised of the particles and the binder material; depositing the agglomerates onto the porous walls of the plugged honeycomb body; wherein the agglomerates are disposed on, or in, or both on and in, the porous walls.