A stinky collar can ruin the pleasures of a freshly groomed dog. But how do you clean a dog collar without damaging the webbing material or hardware? Put a couple of squirts of dog shampoo (which will help prevent skin irritation) in a bowl and fill the bowl with hot water. Let your dog’s collar soak for about 15 minutes. Rub the collar against itself to extract any ground-in dirt. If necessary, apply extra shampoo directly to the collar. Avoid using a brush, which could damage the material. Rinse the collar under running water and hang to dry. If you need to speed up the drying, use a towel to remove excess water before hanging.