I concur with the extra bag, John. Another trick I learned from the old Shasta kits - kitty litter. I bring a small amount of kitty litter as another line of defense between the bag layers.
Wag bags have their place in the toolset for backcountry human waste management. A good example of using both effectively is Mt Shasta. There's a really nice composting toilet at the Sierra Club hut (Horse Camp 8,000 ft) and then you are required to use a wag bag above that point (which is typically snow covered during the hiking season). Another toilet at Helen Lake 10,000ft would be difficult to maintain in the snow, but it's being done with mixed results on other mountains in the Northwest. The Shasta "hybrid" system gives people a choice of camping near a nice toilet or camping higher up in the snow and using a wag bag. It seems to be working pretty well overall. As with any system, it's not foolproof because there's a small percentage of fools anywhere you go.
In one of my letters to Inyo management, I suggested trying a similar approach as Shasta, with new toilets at Outpost Camp and wag bags required above. After a few years of positive experience (assuming the Rangers support the effort) the idea of toilets at Trail Camp could be reconsidered.
