So before 5.4 droped the only way to obtain one of these elxir's was from farming the rare Krol the Blade - NPC - World of Warcraft
with a 9% drop rate, and having to fight 2-3 other people waiting patiently. Now it seems much like all the previous items originally obtain from killing a rare on pandaria most can be found from looting certain items laying around the timeless isle or by killing a rare here too. The respawn rates are much better though.
But today were going to be summoning Archiereus of Flame - NPC - World of Warcraft Mind you his drop chance is much lower than Krul the blade sitting at 3%. You don't have to wait anywhere from 30mins-1hr for him to respawn. What your going to need to do is buy a few Scroll of Challenge - Item - World of Warcraft Now the stone to which u need to be at has a 10min cool down. So when your stone is down simply party with a friend on another realm, And use their stone. * you might want to tell people in general ur summoning him, as most often trying to get to him while the Adds are up might be difficult, and killing him with alot of people is faster imo * So basically you went from a 30min to 1hr wait for a 9% drop rate to kill him on ur server jump to another summon and kill again avging out at 12+% making downtime a better chance of you obtaining your elixir for your alts.