Wash the brush, Nitro and what else

was I about to say ;)
and how does this work now? my boss himself didn't know either.
A coworker said something about special thinner. or is that nonsense too?

The solvent of the coating material is always suitable.

so with spirit [spiritus] he should be able to be softened again?

so with spiritus, it should be possible to soften it again?

"Brush washing" should be done when the brush is still soft and not dried into the coating material. If the bristles/hairs are already hard, the brush can usually be thrown away.

they are still not hard, not even today. just slightly dried out. but why has all the Nitro disappeared, I had filled the small bucket up to 1/5 ;)

You can't know everything, right? but another question, would it help if you put the brush in strong paint stripper and cover it with foil overnight?