I tried soaking some old brushes in Murphy’s oil soap after reading this thread, but my results were disappointing. The brushes all fanned out after soaking them for 24+ hours and then rinsing and drying them. They were all old brushes that I wasn’t using anymore, so it was no great loss, but I ended up throwing most of them away.
Sorry about that Tom, I didn’t have that issue at all. After they soak, I wash them and dip them into boiling water to get shape back. Not really sure why yours fanned out. I guess it make a difference what kind of bristles. I just have cheap brushes from Michaels, the artist pro series but compared to what real pros use, I’m sure mine are cheap.