Cauldron of Thunder should not be usable after Druidic Ritual is completed.
1e_Luis/Quests/Druidic Ritual shows that you can no longer dip meats into the Cauldron of Thunder once Druidic Ritual is complete. Currently in OpenRSC there is no condition on the time period during which the cauldron is usable.
Also unfortunately, no one ever documented if you could dip meat into the cauldron previous to kaqmeex telling you the location of the cauldron & that he needs the meats. I believe this is probably the behavior, but we will never know. Compare with OSRS if you want to, personally i would just "guess" that you are not able to dip meat into the Cauldron of Thunder before the quest has begun.