i think this is actually the best advice here. in 4lo the clutch is the most forgiving.
i don't agree on no gas techniques as that's what leads to the jerking because many, many manual vehicles actually need a little bit of gas. i can get my truck rolling without but it's way easier when i give it a little bit of gas.
after the addendum i'll also would go with hill clutching eventually. start on flat though.
if you're gonna teach him shifting by sound you might as well teach him to shift w/o the clutch. the sounds will sink in faster.. 2000rpm is best for mpgs; 3000rpm is better for performance.. the first is more forgiving and the gears go in pretty easy w/o clutch. the acceleration isn't there but no jerking either.