If the definition needed for your a priori argument is provided up front then, indeed, you can manage that. The main thing that strikes me about "the supernatural" as a term is that such a definition is often not forthcoming in these debates. My method is designed to get around this problem automatically. Admittedly if the X they present can be ruled out through logic alone then no discussion of evidence is required. All the same, the advantage of the get-specific approach is they immediately lose the argument, because they jump straight into an example you can't struggle to address, especially since the burden of proof is then on them. And this works even if they don't define "supernatural" in such a way that the contradictions discussed above can be obtained. Such a definition would undo itself through the necessary conditions it contains. Unfortunately, some conceptions of the supernatural have sufficient conditions. "Imagine if you could make an object come into existence by drawing it with special equipment, like Penny Crayon. Well, that's supernatural."