I originally purchased these at Sephora right before my wedding a few years ago, because we were getting married outside, and I sweat like crazy. They really do work!
I use these on my armpits, around my hairline, my neck/back of neck, feet, etc. I did find it did not work 100% on my hands, but my hands do not sweat as much.
They do not have a weird smell, and the dryness seems to last about 4-8 hours, depending on the situation (heat, etc). They are a little sticky, but not really bad. It did okay under my makeup as well, although I did not use all over my entire face.