People overreact to aluminum. Elemental aluminum might possibly cause some problems, but aluminum compounds really shouldn’t be any big threat. It’s very difficult to get pure aluminum out of a compound, and I can’t imagine why any biological process would do so. Meanwhile, it’s also the third most abundant element in the Earth’s crust, mostly in the form of various oxides, so if aluminum oxide were bad for us, we’d all be dead by now.
Is this the same product as we might see in a cooking store that claims to remove garlic & fish smells from your hands if you rub it while running cold water over your hands? I saw one a few days ago, it was a smooth metal “stone”, shaped perfectly for skipping. I don’t remember if I checked the package to see what it was made from.
No - it’s a big crystal of alum. AFAIK there are non-alum crystals available too (have no clue what is in them though).
There was another thread about the metal soap thing. This is quite different.
I’ve been using the stone for years now- but generally only when camping. It works very well, and doesn’t have any scent (which is why I use it while camping). It’s weird, though, because if you’re used to normal anti-perspirants you won’t think you’re actually applying anything ('cause it’s perfectly clear). Sweating is still a deal, but it’s not too bad, since you don’t stink. I also found that I could apply the stone anywhere I stank- feet, groin, behind the ears (!).