Dunno much about it, but isn't aluminium chloride hexahydrate the stuff in antiperspirant that they decided was carcinogenic a few years back?
The theory being if you're spraying it under your arms and all over your lymph glands frequently for a long period of time it's not a good thing.
Could have just been one of those scares though - when I was a kid I was told eating burnt toast would give you cancer!