After my friends and I walked the Bruce Trail for 5 days (rocks, rocks, rocks, some roads, lotsa forest, rocks...) I had a couple nasty blisters. I'm a Diabetic, which means I don't heal very well, especially on my extremities. One of my friends put this Buy Band-Aid Advanced Healing Blister, Cushions Online at drugstore.com
on my baby toe, and told me to keep it on until the band-aid fell off, in the shower and everything - it dried out the blister, or cushioned it, or something, but it healed beautifully. I was worried about it cutting the circulation off, but it wasn't on tight enough to cause damage.
I hope your feet feel better soon! Blisters suck.