What would be the best tuck pointing temporary alternative?
It sounds like you're asking how to apply a temporary fix to missing mortar. Honestly, filling in the holes is already 50% of the work. You might as well clean out the failing mortar first and do the job right.
Proper tuck point repair does not require significant skill or investment:

Cut the failing mortar joints with an angle grinder.
Remove the mortar with a rotary hammer or just a chisel.
Clean the joints.
Apply new mortar with a trowel and tuckpointer.
Clean errant mortar off the bricks

But if you really want to skimp on the job, you could skip removing the old mortar and just add new mortar to the major holes. Then when you're ready you can cut out problem mortar as described above.