Is it the cover you want to wash?

I have calico liners for the bean bags as well, and i wash them with the beans still inside. I just chuck them in the shower, squirt a bit of washing powder or disenfectant and 'scrumple' them then rinse til the water is clear. (It's probably easier in bath but we don't have one). Then put them outside to dry.

. My bean bags are for the dogs so they get pretty stinky, but this cleans them pretty well.