...on the SSS [VI] - Flossing can be accomplished using a 12 to 18" leader. The issue is far more complicated than what is viewed on the surface. To ban flossing, would also intail banning flyfishing with a swung or drifted wet fly. It could also impeed an angler's gear choice, such as corkies, glo's, worms and other small drifted gear.[of which all mentioned can floss fish]
Flossing is not sporting, but in the same breath, it is damn near impossible to prove a lip hooked fish did not strike the anglers presentation.