Neverwinter Nights 2 Greatest Thief Quest

I've been stuck for days with this quest, getting the code and the key from the collector is quite easy but i never have found how to come up with getting the key at the fireplace. I have wielded armors and weapons with fire resistance, even got 0 damage when trying to reach the key but i still could not manage to get it. i saw the empty bottle in the kitchen i just did not know where to get the water, was i dumb or you just wouldn't expect that the bottle should be placed into the vase.

I've been to forums and all i get is clue. its been two days until i managed to figure it out and finished all the other side quests except the Greatest thief Quest at the Collectors Mansion.

So, to end this misery, i am posting in how i managed to enter through the Collectors Mansion's vault:

After entering from the door in front of the graveyard at the Blacklake district. Go ahead straight to the kitchen, you may fight all the guards if you want or you can use your hide and sneak skill to walk past through them, i prefer to fight to get some exp.

You may want to tie up the servant or just leave them be. Get the empty bottle from the wash basin and place it inside the vase right beside the wash basin location to fill it with water.

Proceed to a room near the stairs and talk to Vania, use her as a hostage. Talk to the collector and then get the ship painting by the sea on the wall and use it to get the key from the collector.

Now, go outside and get the book Numerological Nursery Rhymes from the bookcase, it should read:

Nine are we when taken all three.
Last one slain, then six remain.
None survive our first less five.

from the rhyme you will get the code combination as 513.

proceed to the fireplace use the bottled water to put the fire off and then get the key. Use it to open the vault.