You've heard of cloth diapers, but have you explored Pull-Ups? I’ve been wanting reusable pull-ups in our house for about 4 years now, as both of my kids are heavy bedwetters.
I found and purchased four pairs of SuperUndies. After searching for used pairs with no-luck due to demand, I went ahead and purchased directly from the website. I had high hopes for these, and at $33/ea, it took some time to justify the cost, but I was determined to stop dropping 2 pull-ups in the garbage every morning. These overnight undies aren't plastic-free, as they are lined with plastic, but they are cheaper and less wasteful than disposables over the long-term.
I am sorry to say this eco-option has NOT been a success in our situation. Both kids are such heavy wetters that the fabric just doesn’t wick the urine away well enough, and we ended up with skin rashes and open sores. To boot, we had leaky pull-ups and many mornings of washing sheets. So unfortunately we’ve had to move back to disposables.
If you have light bedwetters I would still recommend giving these pull-ups a try, as I've had several friends that were successful at ditching the princess overnighters. One advantage to cloth pull-ups is that your kids might not like the bulkiness and will train themselves out of them faster. On the other hand, if you've got heavy bedwetters, it might just be a matter of time until their bodies and hormones can help them wake-up in the middle of the night.