uhh, salt in sltw turns to sltw. using spng to drain sltw from watr, you get saturated sponge and salt, that salt becomes sltw, saturated sponge is dried for watr. Also, he never said duping spng itself! the title was how do i make WATER!
The first comment in the thread said "With spng duplication, not glow-ptnm or smth like that" so yes he did say SPNG duplication.