Its called Flesh to Salt on basically any creature large or larger. If you get less than 2k gold for each casting of that spell then you're not trying hard enough.
In a similar vein, Wall of Salt is a 4th level spell from Sandstorm that creates a salt wall with an area of one 5 foot by 5 foot square per level and a thickness of one inch per level. I'll save everyone the trouble of looking it up and point out that salt weighs a little over 135.156 pounds per cubic foot and is a trade good with a value of 5 gp per pound in D&D.
At 7th level, when it's first possible to cast this spell, it produces 68,987.87 gp worth of salt. At 20th level, it produces 563,150 gp worth of salt. A wizard can cast this spell 24 times per day at 20th level, not counting bonus spells, for 13,515,600 gp per day.
Given that salt is literally worth its weight in silver in this game, allowing players to freely create mass quantities of it was a silly idea.