As I was reading this it struck me that the use of a spice ball or muslin bag should be unnecessary.
I've watched the bases being made from the Malik and east live webcams and they use a few bay leaves, some cinnamon stick, star anise etc., all the usual stuff. Now, do you really think they are going to fish about in one of those bloody great stock pots they make these bases in to remove these whole spices? Course they're not! They just blend them up with the rest of the base.
So by that reasoning all you need to do is pre-grind your whole spices and add those in instead of adding them whole, although you would neeed to add substantially less of the ground stuff.
There you go, no more need of muslin bags and spice balls (I reckon!)