I use the lid on my Webber kettle bbq all the time. As soon as the sausages/burgers start spitting and you get a flare up, shut the inlet vent, bung the lid on for a couple of minutes, the flames die off straight away. I also keep the fire to one side of the grate, Brown the meat over the coals to get the colour, then move them from the direct heat, pop the lid on and let them "oven" cook till they're done.