This doesn't work as an antiperspirant, but....
Male here.  I've been looking for natural antiperspirants/deodorants for the past year or so.  I haven't found anything that really works.  This is advertised as an antiperspirant, which it should not be, as it doesn't stop sweat.  What it does do, like a champ, is stop odor.  At first, it was suspect, b/c it was failing.  Then I realized that, as it is very crumbly, I should rub it in a bit more; so, I apply it, then use a finger to rub it in a bit.  It seems to apply a bit more easily when fresh out of the shower and there's still a bit of moisture on the skin.  I put it on in the morning, and even on days when I hit the gym during lunch and don't have time to shower, this doesn't fail.  I've really been impressed with this in that regard.  I would've given it 5 stars, but like I said, it is (falsely) advertised as an antiperspirant.  It will leave some coloration on shirts, but I wear these https://www.amazon.com/gp/product/B075ZQGVVQ underarm pads as well, so it's not an issue.
Rating: 4 stars