Tiny bacteria (staphylococcus hominis) live in your armpit, gobbling up your sebum and sweat and excreting a waste product that creates a rank smell.
PITZ annihilates this little bacteria, culling it's colonies and eliminating the reason for the foul smell. Simple as that.
Rub a few pumps of PITZ between your hands and then apply to each armpit. Apply every morning for best results. Takes a few days of application to start working. Also best to apply morning and night for the first few days of use.
SIDENOTE:
PITZ is basically a stripped-down version of the Bacteria Blaster gel toner used to kill acne. I was using bacteria blaster as a deodorant for years and finally made a version geared for the underarm. Pitz uses a combination of malic and tartaric acids combined with green tea polyphenols and high levels of lactobacillus ferment to instantly wipe out all bacteria in the armpit.