There was talk of a scalding hazard if full shutoffs were used mostly aimed at protecting children. The water store shutoffs mentioned above do a good job of full shutoff but tend to wear out. I buy them five at a time and carry spares.
I have also made a full shutoff by buying a diverter valve at Home Depot and capping the unused side.
2001 Winnebago Adventurer, 35U, W-20 8.1
F+R Trac bars, F+R sway bars, SafTsteer, F Sumo Springs, 4 Koni FSDs