I've been doing my own interior and exterior painting for probably eons. This hand tool is the best thing for cleaning my paint brushes. One side of the head has what looks like brass wire bristles and the other side has metal spikes to separate the bristles of the paint brush. I've even used it on brushes that have been left with accumulated dried paint residue for very long periods of time by people who didn't understand you should take good care of your paint brushes. (just wanted you to know it wasn't me! ha) It makes your brushes look like new, it's inexpensive and there are no complicated directions to follow. Try it!