Amun wrote:
....

You did say synthetic bristles right ?

Any solvent that will soften the paint will turn the whole brush to goo.
....

Not true...

There are any number of "brush restorer" products that will work well.

I've found a couple of the newer citric-based to work quite well, in
fact. Takes a couple of days sitting, but if the brush is a real
quality brush, well worth the time and definitely not the abuse.