I remember the real nappy lady coming to our NCT class to get us to consider the environment. She was explaining how you put the disposable liner inside the nappy and I had to ask if the liner was biodegradable. Nope!
She then went on to tell us about the nappy bin you put them in and how they would come and collect them to wash. Apparently mass washing them in batches is better in the long run, for some reason. My wife asked how, once we had bought our real nappies available in a variety of colours and designs, they would get the right nappies back to the right parents. They couldn't, you just handed over x amount of nappies and got x amount back, but it was OK bececause they were sterile clean and you'd be using the non-biodegradable liners anyway.
This prompted another guy to ask how much it cost to keep the electric powered nappy enviro-truck on the road. Guess what? They used a normal diesel truck to drive around Barnet collecting shat-in nappies.
We use Pampers.