How to restore flexibility to the hairs of a brush become hard after use.
Bring white vinegar to a boil or in the microwave.
Pour it into a container to be thrown away.
Dip the brush by pressing the bristles to accelerate the penetration of the vinegar.
Wipe off paint deposits on the pot.
Continue to soften the hair by renewing soaking in the vinegar.
Finish by rinsing with white-spirit with a cloth.
Between two sites, surround the bristles with a tightly wrapped food film. It will be ready for use again.
The vapors released by the hot vinegar are slightly suffocating but without danger.