1. get rid of cat. [it'll do it again]
2. make small amount of 3% hydrogen peroxide and very small amount of liquid detergent.
3. using scrub brush, work small amount of this into the crusted mess you currently have
4. brush/vacuum off [borrow vacuum as needed]
5. repeat steps 3 & 4 several times until baking soda is used up.
6. evaluate result
7. if there's more baking soda yet, repeat steps 2 thru 6 if you're getting positive results.
8. if you haven't gotten rid of the cat yet, take positive steps to prevent cat from getting close to the bed -- keep bedroom door closed, keep cat outdoors only, keep cat in indestructible bathroom only, etc.
9. after cat does it again -- break down, cry, and then get rid of cat. [In most areas, you can just throw the offender outside and then soak it liberally with garden hose until it retreats.]