the problem with salt is it is difficult to get rid of, and non-specific. For driveway cracks it might be ok, but boiling water is still much safer and harder to fuck up.

Boiling water is really useful too, since the boiling damages the plant in a way that pathogens can enter the plant, which then eat/destroy the roots which usually result in regrowth.

Bacteria repopulate in like no time at all.