Something isn't right with this zone/encounter. Tonight we zoned in 3 groups and 4-5 healers (because the rest of our raid wasn't flagged) and successfully cleared it.
*** WARNING SPOILERS ***
I assume being swallowed is suppose to be the key to this fight. But we basically skipped it and after 45-50 minutes of a slow burn he died. There was no strategy nor did we do anything special, just stood in front of him and melee auto attacked and cured the poison AE. Surely that's not the intention of this encounter.