I always keep a bottle of fabric softener in my shop. (It doesn’t have to be name brand but the cheap stuff from the dollar store doesn’t work well). I use a half and half mixture to soak the bristles of brushes that need to be washed. It works on natural and synthetic brushes. Apparently it breaks down the acrylic/latex binders, and makes the brushes much easier to clean while cutting water waste.
I also add a tablespoon or two and a bit of water to thickened paint – it helps the brushability.
It also helps remove paint from material or clothes that you don’t want paint on – douse it immediately in fabric softener and wash it before the softener dries.
If scents bother you then look for unscented softener.