If the pedals are standard Fr threading, they are 14Mx1.25 thread which for the length of the pedal thread is so close to the 20 TPI of modern pedals (9/16" nominal)
that you will only have to remove about 20-25 thousandths of metal with the taps. In a pinch any oil will do though cutting oil is preferred, you can get cutting oil
at HD/Lowes in the plumbing dept. but if this will be your only threading job any lube will suffice for a one-shot job. The advice to turn the tap no more than 1/2 or 3/4 turn
and then reversing the tap at least 1/4 turn is important as this breaks the chip you are gouging out and facilitates the cutting action with standard taps.