Not sure on the official tacticas but this works for us.
Get a RDPS to manage the adds if possible. Don't DPS the red adds get the tank to pick them up. If a blue add spawns release a red, pew pew the blue and it will pull the red add to him and explode. Same if a red add is spawned release the blue add and pew it.
The first run we did we could not get the reaction to work so after a few wipes we just DPSed the red adds down then killed the boss. This is definitely not the "official" way to do it.
Merc/Mara DPS Sorc Healer Jugg tank