I soak in warm, soapy water (dish soap or laundry detergent, and just keep working on it with a toothbrush, comb, other brush or whatever works. It won't be perfect, but better than before.

Soak in ammonia and water mixture..1/4c.ammonia to 1c. water. Works for combs as well.

First I comb out the loose hair, then I wet the brush thoroughly, then apply some shampoo, just a small amount. Did I mention I have 2 hairbrushes? I apply the shampoo, then rub the bristles against each other, one brush in each hand. Then rinse, shake off excess water, then hang face-down so they will dry quickly. Hope this makes sense.

Toss them in the washer when you do a load of towels. They will come out sparkling clean. Don't do this if they have wooden handles though.

There are made wire brushes for getting all that fuzzout of the base of the bristles....I think Fuller makes them. Then soal in an ammonia solution, as Patsyann says.
Linda C

I soak mine overnight in a soapy weak bleach
water solution. than run a comb through it the next morning, goopy fuzzy stuff comes right out
oakleif

I prefer Jannie's method as it works very well. If you use hairspray or gel, then the ammonia solution is usually better. I found that 2 brushes cleaning each other does a better job faster than the special cleaning brush (yes, it's Fuller's). Don't forget to clean the brushes each time you shampoo to help prevent a buildup of the fibers.

I thank you all for so much advice.
I will certainly try these tips...
-Saly

I stick mine in the dishwasher.

I tried the dishwasher once and the plastic handles melted. Dishwashers can take plastics that are rated /1\ or /2\ but not /5\ and it is not required that the number be imbossed on hairbrushes.

Dishwasher is fine if you skip the heated dry cycle. We wash a lot of plastics so never use the heated dry at all. Keep plastics in the top rack, too.

My niece who owns a beauty shop told me to soak in 1/2 bleach/1/2 warm water solution- no hair removal required; then rinse well. I use a large cheap vase & it works beautifully..no scrubby dub, dubbing needed!
Suzi