According to the website, "Brush Magic is a powerful, non flammable brush cleaner for the rapid cleaning of all types of wet or dried paints from brushes etc."
Sadly, the space available precluded the before and after shots of the brushes I tested the cleaning product on. That's a pity as the stuff really works well. I've tried similar products for rejuvenating paint brushes in the past and none have worked nearly as well.
As a test, I tried it on three brushes – a couple of Trumpeter synthetic brushes and a very old bristle brush. All three had paint build-up that had hardened many months ago. You can see from the photo that two of the brushes changed colour, in a good way, and the other looked a bit happier. Since this last one was bought cheaply from Beatties when they had a shop in central Birmingham, you can work out how old it might be - older than some readers of this blog!