Ivory soap, Mineral oil, Flea comb, WD 40, and a pressure washer. Why not?
I once read that paint brushes are the artist's little friends, a friendship which must be reciprocal for one's brushes to perform up to par. I admit that I really don't keep up my end of this friendship very well. Although I ask for a lot from my little friends, I tend to leave my used brushes sitting in jars and cans for months before I get around to cleaning them. Who has time? For those who only clean their brushes semi- annually, here are some tips on industrial grade artist's brush cleaning techniques. Disclaimer: It is much better to take care of your tools and wash your brushes every night. Don't try this at home kids!
some dirty brushes. I havent cleaned any brushes for months, Im beginning to run out....time to clean them.
brushes with dried paint are soaked in mineral oil. Surprisingly, letting paint dry in a brush helps it keep it's shape...
brush is washed with ivory bar soap until dried paint loosens.
I use a flea comb to get out the dried paint now. Then I wash it again with soap until most of the pigment is out...
Things get a little unorthodox here. I spray the brush with w-d 40 to loosen up any residual pigment.
...Then I blast each brush with a pressure washer! This gets out all traces of soap and paint. One must be careful doing this. And don't try it indoors, kids!
...after the better part of two days, I've brought hundreds of my little friends back to life, ready once again to get down to business. Again, it's better to clean them as you use them. Someday I'll try that.