Kolto was a healing seltzer and vitamin supplement that occurred naturally within the global oceans of Manaan. In the millennia before the discovery of Thyferra and the bacta originally produced there, it was used as a panacea by nearly every civilized nation-state in the galaxy. Except the Mandalorians, but then, they're not exactly civilized. Kolto was the subject of a major, decades-long class action lawsuit that drove the entire planet of Manaan into bankruptcy. Manufacturers of bacta learned their lesson and lawyered up hard.