After a scrub brush has been used, it needs to be rinsed thoroughly, to dislodge any particles or debris that may be stuck in the bristles. A gentle brushing of the bristles under running water will help remove debris. It's tempting to soak our brushes to remove any dirt, but this can actually damage, weaken, or even remove the bristles from our scrub brushes.
Once the brush has been thoroughly rinsed, it needs to thoroughly dry. Most sour smelling and moldy brushes happens when a still wet brush is stored away. Before you put any brushes away, make sure they are thoroughly dried. Do not rest a brush on it's own bristles to dry. This will bend and warp the scrub brush. Hanging the scrub brush from a hook can allow thorough drying and easy access.
Brushes that are discolored, have a sour smell, or are warped should be replaced. Depending on the quality of the brush, how well it is maintained, and usage, a brush may last anywhere from one to four months.