A pseudo-plastic or thixotropic carrier having anti-malodorous components dissolved or suspended therein is sprayed on the internal surfaces of an ostomy bag or pouch. The viscoelastic properties of the carrier allow the composition to be conveniently dispensed from a spray bottle into the ostomy bag and retained on the inner walls thereof without being displaced therefrom by incoming waste during use of the ostomy bag. This allows the composition to continue to deodorize the ostomy bag headspace even after waste material begins to fill the bag.