The odor of a smelly shower drain can be eliminated by removing debris from the drain. Discarding the odor-causing material in the garbage outside the home ensures the smell does not invade other areas. Boiling water dissolves oils and grease deposited on the sides of the pipe in the drain, which add to the smell. Baking soda sweetens the smell of the drain.
Every time a family member uses the shower, more hair builds up in the drain. This hair provides the nutrients to encourage growth of bacteria in the moist drain environment. Clean the screen by removing the screws that hold it in place. A straightened wire hanger with a small hook bent at one end makes it easy to fish out other materials that are collecting in the drain. As an added benefit, a cleared drain allows water from the shower to empty without standing when the shower is in use.
Soaps, shampoos and body oils build up inside shower drains as an additional odor source. Pouring a pot of boiling water down the drain after cleaning out the hair and other debris dissolves this mixture and improves the smell inside the shower.
Baking soda helps to absorb and neutralize odors. Adding 1/2 cup to the drain once per month with warm running water keeps the drain smelling fresh.