Ben , I have also bought this 16oz bottle of liquid flux to refill those little dropper bottles ( the snout simply pops off to refill) , I use more flux than solder & tend to run out of it before I do solder. A 16 oz will last a very long time.
Harris part number SCLF16. Stay-Clean General Purpose Liquid Flux. A general purpose zinc chloride flux for soldering with all soft solders use with tin-lead solder, tin-antimony solder, Stay-Brite...