I personally do not know very many homeless people in campgrounds that have a need to rummage through dumpsters. Maybe in some of the inner cities, yes, but campgrounds?
We've had a port-a-potty for some 28 years now. Started using it with our first tent (as a family), then the pop-up camper, then in each of our travel trailers, especially at home in the camper for driveway camps, so I do not have to dump holding tanks. But, we've never use the kind that takes the bags. We've always used the kind you can remove the bucket and dump it (down the toilet). Our 27 plus year old port-a-potty finally bit the dust, and we bought another one. During power outages at home, it's priceless to have!
Get rid of the bag and switch to the bucket type and then you can dump it down any toilet, or even a pit toilet wherever you're at.