If a country were to standardize, say, drink bottles, detergent bottles, etc, then this is already a solved problem. Just have a machine clean the bottles to wash away dirt and remove labels, then run it through some image processing software to auto detect any residue. Anything within a certain threshold could either be accepted as clean or needing an extra wash, and anything over a certain % of dirtiness or having undergone N number of washes without getting clean is sent off to be melted down and recycled.
Once it's standardized, the software is made, done, and ready to deploy everywhere without any changes (until the government approves new bottle designs). Facilities would be cheap to build. The only problem is every drink manufacturer in the world would oppose it since they can't make goofily shaped bottles with cartoonish logos everywhere.
Wouldn't be surprised if it was also beneficial for the soda companies - standardised bottles would be cheaper to produce/acquire, bottling equipment as well.
For HN readers, this is an example of "don't make perfect the enemy of good."
If even 10% of the bottles were nasty, there are machines that can handle that.
Just like Europe's progress in standardizing chargers, we need to go back to standard bottle sizes.
One of the best examples is the Beer Store in Ontario, Canada. All brewers have to use stubby brown bottles, and achieved 99% reuse in modern times:
"Between 2013-2014, the Beer Store achieved a system-wide recovery and re-use rate of 99 per cent for the industry standard bottles, which are reused 12 to 15 times."
They accomplished such phenomenal reuse that the bottles wore out. So much for excuses, eh?
I'm not an expert in this so idk how difficult it is to ensure this but unless the system is perfect it can't be used.
If we could do it 50 years ago, we can do it now. It's a solved problem.
Cleaning is more labor intensive than recycling, and if the cost of cleaning is less than the cost of recycling, you'll end up cleaning it. This is only possible in developing countries where it's more economical to use low-cost labor than setting up an expensive recycling facility.
As recycling technology gets better and cheaper, you'll see fewer countries opt for cleaning over recycling.