FACE wrote:
....

A big thanks to all that have replied. All sound like good ideas.

I don't know about beating on it w/ a hammer...

The in-the-freezer-overnight will become a new thing of mine. ..

Just clean the damn brush when you've finished using it and get avoid of
the problem...doesn't take 30 minutes and is far better for the
brush. The one thing whoever talked about solvents had correct is that
removing dried paint from a brush is never absolutely complete and the
brush will not be as good as it was, ever. How much you lose depends on
how bad you let it get and how good a brush it was originally.

The solvents are also attractive. I had considered gasoline overnight but
that may turn the synthetic bristles to goo as someone said. However, white
vinegar sounds pretty benign.

Besides giving me a good laugh, beating the bristles with a hammer and
powdering the dry paint then combing it out also sounds reasonable.

Not if you want a decent brush to work with when you're done. You'll
break darn near every bristle and weaken those you don't. You'll be
picking bristles out of the paint continuously.

I just bought a new wire brush ...

A bristle brush is not a common wire brush.
....

Question to Pat: Do you use the Big Orange citrus cleaner full strength or
in a dilution? I am also using Zep housewash.

Not Pat, but you use it according the instructions on the container.
Don't know the particular brand and sometimes the same brands are sold
in both concentrate or ready-to-use containers.