You need to wash your brushes at least once a month no matter its a bristle brush, a plastic brush or a rubber brush.

• Remove hair from the brush. You can use a comb to go through the bristles or use your hands to pick the hair up.
• Fill a plastic bowl with lukewarm water
• Add a dash of washing up liquid into the bowl
• Gently dip the bristles into the water, not the whole brush
• Use your finger to clean in between the bristles
• Change the bowl of soapy water to clean plain water
• Dip the bristles in the water to rinse
• Shake the brush well to get rid of the excess water
• Use a soft dry towel to squeeze the bristles
• Place the brush face down on an edge of a table in an airy room to allow it dry naturally.