Strategy
There is no guaranteed method to accomplish this achievement yet, but a video of the acheivement can be seen here: http://au.youtube.com/watch?v=lsXf91M20VY
This was done by jumping off the bridge above the Crushers that initiate Hadronox's ascent up the tunnel to where it is normally fought, and moving down the tunnel towards where it can be seen fighting Nerubians. A tank and healer remain towards the top of the tunnel to tank mobs coming down, while the rest of the group including a class capable of resurrecting players, and self resurrecting via a soulstone or reincarnation run into Hadronox's room and take a hard right hand turn to sit in the north western corner.
The group is then allowed to wipe, where the tank and healer are hopefully within resurrection range. Soulstone/Reincarnation is used, and the group is reformed in the safe area of the room.
Due to the nature of the fight and the method of wiping, a shaman and warlock are good for both summons and heroism/bloodlust.
After the group is ready and buffed up, timing of the pull is up to the discretion of whoever is tanking. Keep in mind, the adds from the tunnel should not be tanked, as they add DPS and debuffs to Hadronox making it die faster.
Heroism is used and heavy dps is applied and Hadronox will hopefully die before casting Leech Poison on everything, regenerating to full.
Additional Notes
It is worth noting that if an immense number of ads are tanked at the top of the tunnel that Hadronox travels up, if enough are tanked to the point where the group is forced to wipe, then it's possible that the sheer volume of mobs that make it down at the same time could possibly be enough to kill Hadronox without the assistance of the group.
This could be worth investigation.