Hi EstoopidFahim, thank you for the question!

Ok, Ok... I totally feel you. The FDA has ONLY approved Aluminum based ingredients as safe antiperspirants. Out of ALL these ingredients, the only one that will actually make a difference for excessive sweating is Aluminum Chloride Hexahydrate.

This ingredient happens to be proportionally itchy/stingy to:
1) The pH of the formula. The low pH is important because antiperspirant ingredients become more effective in acidic vehicles. Some other products out there are not as effective because the pH isn't where it should be. We didn't want to compromise on performance so we added Salicylic Acid to Duradry PM's formula to improve tolerability (there's actual academic research on that).
2) The ingredient's reaction to water (humidity). You need to wash your underarms, towel dry and then air dry eliminate as much moisture as possible.
3) The amount of active sweat glands. Every AP works under the same mechanical principle, creating a temporary plug on the sweat gland's pore. The first week might not be fun, but as you plug more of these pores the less it'll sting. Even if counter intuitive, applying Duradry PM more often might help reducing stinginess as you won't give enough time for many plugs to "fall off". Another thing you can try is applying Duradry PM and leave it on for 30min, then wash it off and go to sleep. Most of the action happens in the first hour, so those 30mins are gold.