Buy the Zoonza
The Zoonza is a great and long lasting paintbrush
The Zoonza is a squishy hollow tube made for sucking up water. This prevents the bristles of the brush from falling out while cleaning. It is also refillable. The holes are made so that they only release one drop at a time so you don't get too much. The Zoonza can also get just the right amount of water while you are painting with watercolors.