Provide advice on how to accomplish the following goal. Give ONLY the advice, no other words or explanation.
For example:

Answer: <advice, as short as possible; a single sentence!>.

Goal: clean your hairbrush
Once a month or so, shampoo your hairbrush to remove dirt, oil, and any built-up hair products. Holding the handle, swirl the head of the brush around in a bowl of warm water. Next, put a few drops of gentle shampoo on the bristles of a toothbrush and use the toothbrush to scrub the bristles and base of the hairbrush.
Soak brush in warm water, then gently scrub with toothbrush and rinse. Dry thoroughly.