So I've been washing my brushes once every week to once every two weeks, depending on how often I use them.
I use a mixture of baby shampoo, alcohol, dish washing soap and conditioner in equal amounts and pour it into a dish filled with warm water. The dish is filled with just enough water so the bristles can be washed in it, without the ferrule getting into the water...(ideally). So let's say the water has a depth of about 1 cm. I heard that the water should not touch the ferrule - the metal part - otherwise your make-up brushes will get damaged.
Now, I never manage to wash my brushes without the ferrule part getting a little wet and I panic.
Most of my brushes right now, are either no-brand or crown brushes and if I would mess them up I wouldn't be that sad, however I will be receiving my MAC brushes soon and I hope that they will last me a life time, ok, a few decades would do too. :)
After the water's colour changes, I change the washing solution for the rest of the brushes and rinse the bristles of the brush. I wait for the water to run clear. Again the ferrule is getting wet!
In order for the brushes to dry well I first squeeze out the excess water and then lay the brushes flat on a towel. It usually takes several hours up to a day for them to dry.
How do you wash your brushes? Does your ferrule get wet, too?