I think I prefer the capitalist approach and make the user pay:
Maybe we need some kind of disposal certificate number etched on the appliance, where on purchase of a new item, we pay the disposal costs upfront, plus a bond, which gets refunded (with interest) when the item finally gets collected by a council.
Plus it would generate a nice pool of money that could be used to invest/etc. The savings from not being blackmailed into paying for other people's rubbish easily make up the extra bureaucracy involved, most of which can be automated anyway.
Of course fridges etc would cost about £100 more but that is only the true cost, instead of the subsidised price that is advertised at the moment.