If I may add 2 cents worth here. I would caution being too aggressive with the Brillo pressure on the bristles of the brush. I would suspect the detergent of the pad is pretty potent is why it will get the paint out so quickly. I used to do sign writing in the States years ago. I used to clean enamels and water based paint and even ink from brushes.
The best thing to do is to pre-wet the brush before it is used. Water for acrylics, solvent for enamel paints. When cleaning water based from the brush, I used regular bar soap, Lava brand for tough stuff. Wet the palm of your hand, with the bar make a soapy puddle there. With the brush handle Vertical, smoosh the bristles lightly and rotate in circles to bring the soap up the bristles to the ferrule. Rinse and repeat till the puddle has no colour in it. If the bristles tend to dry out of shape, drag the bristles across the bar, shape the soapy bristles with your fingers, let dry and store this way. When ready to use the brush, rinse with water and use.
If you are using enamel, do the same with turps, shape with a non-detergent oil, store this way, clean before using. I knew a sign writer had brushes 25 years old, used hair shampoo and conditioner on his brushes. Hope this generates some thought. This works for common house painting brushes as well. cheers, Bill