Just a thought... for the folks that are recommending antiperspirant for chafing/blisters.... with the armpits as the exception, you should never use anti-perspirant anywhere else, particularly not feet. Deodorant is fine, never anti-perspirant.
On a trip long ago, I sprayed my feet with "deodorant" before a day in the park with new sandals (not even thinking about it also being an antiperspirant). By noon, I was in agony, and checked out my feet closely in the bathroom, and instantly realized that I had killed my feet's ability to perspire, causing them to retain all of the sweat, and they were horribly swollen and red. I washed off the stuff immediately, and within an hour my feet were half the swollen size and continued to actually improve all day. I think I washed them a couple more times, just to be safe.
So -- learn from my mistakes... NEVER antiperspirant. Sweating is a necessary function of your body's cooling system... imagine if you sprayed your legs and feet with it in July before hitting Disney? You could literally have heat stroke!