You LoS them, you dont let them go off, especially Salt Blast is 100% LoS, if you do it correctly, not a single one of those will go off, maybe 1/10 because they lined up weirdly.
The water blast is still LoSable but not all positions are doable, after that its literally Reflect-->CD rotation and making sure your DPS know they need to start interrupting so a second one wont go off in a row.
Considering you are doing +15s i aint even sure why this needs to be asked >_>.
And generally if LoS isnt an option, its literally ...Reflect 1, Pummel 2, Intimidating Shout both, Warstomp both(Tauren ftw
), Shockwave?! if they are still alive, well make your damn DPS interrupt something for a change also.