That's what myself and our Bear does. We just taunt on Srikes. We had a DK previously who's now left, that refused to do that and instead insisted on taunting after the color change, which made overaggroing a massive problem. Taunting on the actual Strike means you only ever have to worry about add threat, and assuming you don't proc trinket right as Ominous spawns you're shiny. To make it easier you can macro your taunt to target Xhul (@focus, @Whatever), so you can just press taunt as the strike goes off on your bossmod.
Just be careful when one of the big adds die, as you can get two Strikes of the same color in a row and by doing it as we do you kind of go into autopilot a bit. It makes the fight fairly easy, in my opinion. Tanking it on 2fps on my laptop keeps it interesting.