A dirty hairbrush is both gross and hard to clean. A small strip of pantyhose can make cleaning up all that hair a breeze.
Simply cut a strip of pantyhose the size of your hairbrush head and place it at the base of the bristles. The bristles will poke through the pantyhose so that you can continue using the brush as normal. Once the brush dips below your cleanliness threshold, simply remove the pantyhose and the hair (and whatever other gunk your hairbrush collects) will come off with it.
18 Awesome Ways to Reuse Old Pantyhose [WonderHowTo]