This is my first prototype lube extruder, since this one I have made a few improvements. The drive rod can now be used with a drill to easily extruder the lube out. I use a beeswax/grease/parafin mix in my Lyman and Star that doesn't require a heater for using in the machines. I've never tried using this with the really hard lubes as I don't use the hard lubes.
You can extrude a little lube to fill up your sizer, or extruder a piece 2-3 foot long. To get the best cut ends, just extrude how much you need or the length you'll sell the lube at and use a blade to cut the lube from the extruder. You will be able to press the blade against the part of the extruder that creates the hollow portion of the lube stick.