How to Clean a Walgreens Cool Mist Humidifier

Fill a small bowl or bucket with 1 part white vinegar and 3 parts water. Dip a cloth into the mixture and wipe down the entire humidifier. Use the cloth and mixture to clean away any mildew, mold and grime from the cool mist humidifier.

Empty both the Walgreens humidifier's base and water reservoir of water. Turn each upside down to drain completely. Wipe away any remaining water with a clean cloth.

Mix demineralizer with water, following the manufacturer's instructions, in a bottle. This amount will vary depending on the strength of the demineralizer -- generally, this is about 1 to 3 caps full. Shake the bottle to mix and then pour the mixture into both the base and the reservoir. Let soak for about 30 to 45 minutes. This will kill any bacteria and rid the reservoir and base of mineral residue.

Mix more demineralizer with water in a separate bowl, and place the humidifier's filter inside to soak and clean it. Let it soak for approximately 30 to 45 minutes as well.

Rinse the cool mist humidifier thoroughly with distilled water after soaking the base, reservoir and filter. Do not use tap water or bottled spring water, as each have minerals and bacteria. Wipe down with a clean, dry cloth and then fill the reservoir with distilled water.