An air treating apparatus for a pet sanitary station, preferably an open, non-enclosed disposable cat litter box, and methods of liquid dosing and mounting said apparatus to an upper wall member integral or attached to the top of a vertical wall of the cat litter box. The apparatus comprises a moisture resistant, preferably paperboard blank folded approximately in-half forming a matchbook like folded apparatus having a top cover, bottom cover, opposing open sides, a convertible open and closing means, absorbent material attached to the bottom cover inside surface, three embodiments for liquid dosing the absorbent material whose fragrance or aroma permeates out said apparatus to treat the air above the cat litter and four embodiments for mounting said apparatus to the upper wall member. The invention includes methods to introduce the pet to a new fragrance, extend the useful life of used cat litter, mount, liquid dose the absorbent material, and open and close the apparatus.