Rock Deodorant?

Who here has tried the crysal rock deo? Just how effective is it?Rock Deodorant?
It doesnt work. I worked with this girl that only used it and she always stunk. But she couldnt smell herself. Lye soap is what i use its great for everything that your skin, its totally pure.
I have used this type of deodorant for a long time, as I have extremely sensitive skin. I have used the version that is the rock, but in a roll on type container so you don't have to hold it in your hand. I would say it works extremely well to combat odor.