Many tradeskilling recipes call for "liquid". For such recipes, liquids from various sources around Norrath would work.

Purchased (from world wide fuel merchants)

• aerated mineral water for 6c
• distilled water for 18c (removed from vendors)

Dropped (various corpse loot/merchant foot)

• The most common was 'saliva' vials (of those, the most common was canine, from gnolls)
• Various other items that were "logically" a liquid, such as vials of slime/muck/goo