1 Taking an oatmeal bath is another popular remedy for soothing the skin and getting rid of rashes. 2  To take an oatmeal bath, you need to mix a cup of colloidal oatmeal in warm bath water and soak in it for about 20 minutes.3  Furthermore, you may sprinkle cornstarch on the affected area.ake sure you wash your skin with a mild soap and water before applying any of these remedies. Moreover, some rashes like heat rashes and swimmer’s itch tend to heal on their own. 1  Ice Therapy. 2  Olive Oil. 3  Aloe Vera Gel. 4  Witch Hazel. 5  Baking Soda. 6  Neem Leaves. 7  Banana Peels.