Yeah, that stuff is awesome
I use that to clean my brushes when nothing else seems to get the paint out and I don't want to risk using something that may hurt the bristles. It even seems to be good to recondition old brushes that I thought couldn't be recovered.
The thing I like about the Gum Arabic is that it makes the brushes hard again like when I bought them in addition to reshaping. I have a hard time doing fine detail with 10/0 - 0 unless they have a bit of stiffness to them.
~ Garth