lather it up with regular hair shampoo, several times through out 2 days. let it rest soaking in the shampoo lather over night. I have a boar that still smells a bit its about 2 months old now. my badgers where easy to de funk. I don't have a horse hair brush.
Yup. Shampoo it then just use it. Don't know about letting it sit in lather overnight, but I guess it can't hurt, unless it has a wooden handle. Then I definitely would not let it sit and soak. I've never used horse hair, either, but I do have a few boar brushes. My Omega 49 took a full month of everyday use before the funk was gone. On the other hand, my Omega 10098 and my Semogue 2000 only took about five or six uses. Never had any funk with any of my badger brushes.
I used borax and shampoo , smell got lighter , picked up a puck of williams used on face and brush , williams sucked for shaving , but seems to clean brush .. smell almost gone , cant wait for restock of cella at west coast shave so I can get all my other shave creams and soaps , may pick up a tube of maka root from bodyshop or a tube of co bigelow local from mall to tide me over and play with new skuttle