The recommended solution prescribes mixing 1/3 Listerine (original), 1/3 baby oil and 1/3 water in a spray bottle. Shake it well before spraying on a dog's itchy spot. The anti-fungal and anti-bacterial properties of Listerine mouthwash are believe to be the reason it could bring temporary relief to a dog's itchy spots.
One veterinarian we asked about this do-it-yourself anti-itch solution said they have not actually heard, much more studied, the effectivity of the Listerine spray on dogs. However, she didn't discount the fact that the mouthwash's acidic and anti-germicidal properties, not to mention the cool minty flavor, could probably bring some immediate comfort to an itchy dog.
After spraying your dog's skin with the mixture of equal parts of Listerine, baby oil and water, carefully massage the problematic skin area and try to spray it into the skin thrice a day.
Another homemade solution uses a mixture of oatmeal and water. Using a blender, grind well a cup of oatmeal until it becomes powder. Mix it with lukewarm water. Slather and rub the resulting pasty oatmeal on the dog's itchy skin to relieve dryness and soothe itchiness. Leave the oatmeal “mudpack” on your dog for at least ten minutes before rinsing it off with warm water.
Final tip: Regularly wipe your dog with a damp towel, especially after they've been outside. This way, allergens on their coat could be removed and would not be absorbed by their skin.