The reviewer above got such amazing results by using this tool along with soaking their brush in a Dawn and diluted vinegar solution!
Promising review:"When I bought this, I was really skeptical. I am grossed out by my hairbrush and clean it all the time. I've soaked it in vinegar and tea tree oil, used a toothbrush, scrubbed it with shampoo, picked it clean by hand — everything you can think of. Still, it's so hard to get the little lint that forms at the base of the brush — they don't dissolve off, and you have to pick them off the bristles one by one because a toothbrush won't even break them up.This thing works amazingly. I don't know why, but it just does — the particular texture of the bristles on this really grabs everything.It scraped the little lint rings right off, and now my brush is cleaner, 10 times as fast." —HeartsofHavoc
Get it from Amazon for $9.95.