Warning: this post contains reference to human waste. (But only briefly.)
I was changing Gregory's nappy tonight. He'd filled it pretty efficiently and pretty full. The results had gone right to the edge of the nappy, but not beyond thankfully, so no need to change his clothes as well. We're not always so lucky, but 9 times out of 10 we are. At home, we use washable nappies. When he goes to nursery, we put him in disposables (to make life easier for the staff). He comes back with soiled clothes about half the occasions he goes to nursery. Some of that is down to how rapidly they change him (lots of little ones in the room, so they mostly work on a schedule rather than when he needs a change). But I think most of it is down to the quality of the nappy.
Now, the arguments for and against washable nappies are pretty well-rehearsed. In favour - they use less energy in producing the nappies, they don't leave hard-to-degrade containers of human excrement in landfill sites, they don't fill up bins and landfill so much, they save money. Against - they're less convenient, require effort to store and wash and dry, there's a higher up-front cost, and washing nappies takes energy too (this last is based on very spurious numbers but is often repeated). The bulk of the arguments for washables are essentially moral ones, and perhaps behind both arguments is a worldview about what really matters.
What doesn't get said often enough (though it's not absent from the debate) is that washable nappies work better than disposables. They hold more waste products, keep them safe for longer, and significantly reduce the risk of nappy rash.
Why is this argument not made more often? I think it's to do with the issue of worldviews. Those who use washable nappies do it because they're green-minded. Those who use disposables do it for convenience. To say that washables are more practical is to cut across these categories, so must be inadmissable in some way.
An interesting question is around modernity. When disposables first came in, they were definitely perceived as the Modern Option. Your parents used washable nappies ("terries"), huge things which could only be fixed with a pin and required a week of soaking before they could be washed. Definitely old-school. Moreover, the very complexity of the manufacturing process of disposables made them attractively Modern. And as David Edgerton describes at length in his masterful book The Shock of the Old, the process by which technologies get labelled as Modern is a very strange one, which belies the fact. Of course, contemporary washable nappies are easy to use and clean, and constantly undergoing 'updates' - but the idea that they're Not Modern persists.
So to green technologies more generally. Whether it's windfarms, hybrid cars, or even just bikes, environmentally-responsible technologies are often sold because they're greener, and the question of their practicality (let alone their modernity) is left to one side. The Prius is an exception of sorts - it's very gadgety - but it's fairly rapidly become associated with wealthy American liberals (Hollywood actors etc) for whom practicality is not the main thing. There's now a hybrid version of the Honda Jazz, a car that's very largely sold for its practicality (we have one, and it is indeed very practical) - it will be interesting to see whether the hybrid version is sold as practical++, or as practical design + green engine.
So: what would happen if manufacturers of green technologies sold them as Modern and practical, instead of as green? It would at the least be interesting to see the results.