Basically, your raid has to be good at keeping sound low.
Searing Flames just absolutely can't get more than 1 tick off.
The adds need to be interrupted and killed immediately.
Nefarian will RANDOMLY, SOMETIMES destroy a gong when you use one--meaning, sometimes you'll have more than you plan for, but try not to use any more gongs than strictly required.
Really, though, it's not that bad. It definitely got nerfed to the ground.
Bring Swiftness Potions to avoid the instagib in the air phase. Good luck