Why didn't the Elves make better use of these waters? What better than to spray opponents with the waters, rendering them senseless?
They could have sent Thorin a 'peace offering' of some food and casks of water when the Dwarf was holed up in the Lonely Mountain.
"Drink up!"
My original thought was to somehow feed this water to Gollum when he was in captivity, as it might have made him more manageable.