Hmmm. I don't know how different cats are with scents than dogs, but I was Nicki's favorite stuffed toys fairly reguarly. I know what you mean, they can get pretty grungy looking. Nicki doesn't seem interested in the toy as soon as I bring it out of the laundry, but she'll always play with it the same day.

Could you perhaps give it a little "sponge bath" in the sink before trying the deep-dunk of the washing machine?