Several ideas like yours have come up before about solving the human waste problem with more policing. The first thing that would happen is people would just not use the bag at all - why leave evidence behind. The other problem is that Inyo has no legal basis to require anyone to use a wag bag, so therefore they can't enforce it. Technically, its a voluntary program. The reason they have no authority is they didn't complete the environmental process necessary to issue a Forest Service Order. As described in this thread, they went forward with Alternative 5 of the Environmental Assessment to remove the toilets and give out wag bags without bothering to complete the environmental process.
Despite this, everyone should use a wag bag and carry it out because it is the right thing to do in this circumstance. Without toilets, there is no other way to go.
