Inositol at GNC, it is the same texture. Unless you have REAL amateur they wont use baking soda or powder.
Your dealer probably does it with a razor blade.
Baby formula or pills
Usually baking soda or powder.... If you have a good coke dealer, he'll probably cut it with baby formula so you don't have that nasty salty taste :P
The best cut is italian baby laxative however anything and I mean anything that remotely resembles white/off white powder will do for some folk. If you want return custom then you are not going to dilute your product with anything to harmful so baby laxative does it for me.