I once washed a good foundation brush with dish soap and watched the bristles shed like a bad haircut. Dish soap strips the oils that keep brush hairs soft, and it loosens the glue that holds the brush together. That mistake cost me a brush I still miss.

What to use instead

You do not need a fancy brush cleaner. A gentle soap works, and the best cheap option is baby shampoo or a mild clarifying shampoo. For synthetic brushes, a drop of gentle hand soap can work, but I stick with baby shampoo for everything.

The other half of the trick is how you wash, not just what you use:

1. Wet the bristles with lukewarm water. Hot water can warp the glue.
2. Swipe the brush over soap in your palm or on a textured mat.
3. Work the soap in with light circles, never pushing water up into the ferrule, the metal part.
4. Rinse until the water runs clear.

Drying matters more than you think

Lay the brushes flat on a towel with the bristles hanging just off the edge, or use a brush tree. Never dry them standing up in a cup. Water runs into the handle, loosens the glue, and that is how brushes fall apart from the inside.

I also learned the hard way to keep water out of the ferrule while washing. Tilt the brush down as you rinse so the water flows away from the handle instead of into it.

How often to wash

Foundation and concealer brushes pick up the most gunk, so I wash those once a week. Eye brushes get a wash every couple of weeks, or right away if I used a cream product. Powder brushes can stretch to three weeks, but I wash everything once a month at minimum, because dirty brushes are also a skin problem waiting to happen.

Six months in with the baby shampoo method, my brushes look and feel better than they did with the dish soap routine. Slow and gentle wins.