For what it is worth....

If it is just a hot spot, a bit of duct tape.

If it a true blister, wash, pierce, drain, a dab of neosporin, and duct tape.

But I wait for the tape to come off in it's own due time. For some reason, it seams to leave a thin callous where the blister had been.

But that is my self-witchdoctoring.