Bigchump,

Not flaming, just my read. As I see it, flossing is snagging. From page 30 of the regulation pamphlet:

"SNAGGING
Attempting to take fish with a hook and line in
such a way that the fish does not voluntarily
take the hook(s) in its mouth. In freshwater,
it is illegal to possess any fish hooked
anywhere other than inside the mouth or on
the head."

So if the point of flossing is to put the line in the fishes mouth without the fish voluntarily doing so, then you are snagging. I don't believe that you can say that because the fish has to open its mouth to breath and the line runs across its jaws, that it is voluntarlily taking the hooks in its mouth. Justify it any way you want, but as I read it, it's illegal.