[10/25 ToC] when to pre pot?

[daemonym]

after my guilds first foray into heroic 25 last night i actually started using indestructible potions (we got rofl stomped from lack of dps). and i know that if you drink it before the pull you can use a second later on. only i was noticing that the CD wasn't ticking away because i think once you talk to the guy to start it 'counts as in combat' so to speak. naturally i want every last second of it that i can have, so i was wondering what the specific time to use it before hand was. if 'combat' starts the moment after you talk to the NPC fine, but if it's like a few moments after or what have you, i'd like any specifics on that i can get. thanks in advance!

[Rhiannon]

For beasts you want to drink it about 5 seconds before the doors open and Gormok enters iirc. For Jaraxus first pull, you can wait ages (though the only physical stress in this fight is on the add tank when a mistress is up, not really worth it imo). Anub'Arak has no intro, and tank death to physical burst shouldn't really be the cause of wipes on Twins attempts either.