Pumice stone (cheap, manual)
PedEgg ($10, electric) REALLY DOES WORK
Go buy a Pedi Egg.
Also, you may have a bacterial infestation on your skin. After you shower in the morning, put some neosporin on your feet. Do that for a week or two.
a callus remover maybe.
white apple cider vinegar
Cheese grater (not kidding, that's what they use at the spa) just soak ur feet first and only do the hard spots