I think it speaks volumes that James original post was nearly 2 years ago.
Adding this technology has a triple cost: machinery investment, increased crew times and increased lorry servicing times between empties (how long does it take to empty and then refill 2 tons of water every time you empty the lorry?)
Councils are notoriously bad at implementing new ideas like this and it doesn't mean that because one has done it the others will all follow suit.
Plus how often are the bins washed and how much do they charge. My customers have 2 bins (landfill and recycle, plus some have green waste bin) and I do the landfill every 4 weeks and the recycles every 8 weeks at £2.50 a go. This Gives an annual bill of about £50 which many will pay. If the bins were washed at every empty the bill would be £130 which isn't the same thing.
I can't see the councils offering free bin cleaning when they've got no money. They're introducing a £25 a year charge for green bins round here. And I can't see the punters paying what the council will want to charge. Bin cleaning tends to run at 3-6% of the population in any one area. If the council charge then the crew is constantly looking down a list to see which bin to wash and which ones not. More time wasted.
The only way this would work is if the EEC or the government suddenly force the councils to wash everyones bin, say twice a year, free of charge for hygiene reasons.
And even then I think the councils would be better to call the local bin cleaner in, offer them a contract to do it and help them gear up for the new equipment through advanced 3 month payment or something. I'd be up for it