I saw the following claim in an article on Runner's World website:
If your feet sweat profusely, this can increase the chance of blisters. Try soaking them in surgical spirit, or even better, three per cent formaldehyde solution once a day. This will help reduce the perspiration.
Is this a valid technique for reducing perspiration in your feet?
Judging from the Wikipedia entry, I don't think I'd want to put formaldehyde on my feet, although surgical spirit doesn't sound as dangerous.