After re-reading this, I realised I wasn't clear on the taxation - this would apply to manufacturers not consumers, thus incentivising them to advertise green credentials as a feature, and to cut down packaging or pass the cost on (at which point most customers would move to the cheaper product).

As far as non-homogeneous packaging goes, if it takes longer than 5sec to separate each bit into homogeneous parts, then I'd class it as non-homogeneous.