Been using Tref for last 50 years. First bought it in a tin about the size of a Tate & Lyle treacle tin – 1lb? for 12/6d!
I dont use it when tapping small dias. in blind holes, e.g., M4 in mild steel, blind hole. Only use a liquid lube which is easy to wash out with paraffin. The liquid jollop was recommended by Guy Lautard – 3 parts Olive oil, 2 parts White Spirit and 1 part Genuine Turpentine, not Turps substitute. It works a treat and in my opinion, smells good. Part of the requirements for no busted taps, along with a sensible size of tapping drill followed by the tap without moving the work, so retaining perfect alignment. Always use a generous size of tap drill.
Going back to tapjollops, the small tubs of Tref, about the size of the old 35mm film containers, lasts ages and then some.
John