You will likely have some 'tolerance stacking', that is, the clearances for each adapter will add up by the number of adapters. If they are a very close fit into each other and the 12 to the actual gun chamber it would be ideal. Now, for a 22LR, or maybe even a 22Mag, it may not matter (though if the stack is kinda 'sloppy' so will your accuracy be). I would think this might even be OK for the std. pistol calibers, but would be leery of doing so with hotter rifle calibers (which it doesnt sound like you want to do anyway).
I just havent seen good enough accuracy reports on the short ones to justify it for practical use. For a survival context I still think a small, accurate 22 handgun would be better for me (accepting that it may not be for you) as an adjunct to my longun, and there I would be tempted to opt for a 20ga., though in reality a 410 may be more practical.