Subject: Is potassium alum - KAI(SO4)2 a negatively or positively charged ion?

  My grandfather was diagnosed with prostate cancer and is pursuing a "chem-free" lifestyle.  He 
switched his deoderant to a potassium alum crystal.  I researched it on the web and found alot of 
different "blah, blah" about it being safe or unsafe, causing Alzheimers etc., and I would appreciate 
some solid science about how the stuff works.  I tried it when I visited him and it works great but I don't 
want t use it if it is racking up aluminum in my brain or his.  The people that sell it all say it can't be 
absorbed due to "negative ion charge".  Is this true or just parrotted marketing whoha?  Looking for 
some heavy metal free peace of mind.  Thank you.

Re: Is potassium alum - KAI(SO4)2 a negatively or positively charged ion?