Yup, I agree those are problems, but not insurmountable ones.

1. Agreed, refundable deposit fees would help the eyesore problem but not the sanitation one. It's not a perfect or a permanent solution, but it would still be an improvement over the status quo, while work continued on something more permanent.

2. This is the biggest challenge. The easiest answer would be to return the bags to the ranger station in Lone Pine. If you can't make it there during normal hours, you don't get your deposit fee back, sorry. Very few bottle recycling stations are open 24 hours either. Or maybe an automated solution would be possible with some kind of scanner to dumpster machine.

3. True, but I don't see this as a big concern. I wasn't thinking that the bags would have any kind of identification attached - in fact it's important that hikers be able to return anybody's bags and get the deposit fees to encourage clean-up. If a few people refuse to even carry WAG bags, that's a problem, but it's no worse than things already are.

I'm not arguing against some kind of toilet solution (llama or solar or otherwise), but that feels difficult to reach and probably years in the future. Why not try to improve the situation in the meantime, with a change that could be put into practice right now?