Mandy has corns on each foot (actually on almost every toe). We use Abreva (2x daily) and Kerasolv (at night with toddler socks over her paws to let it soak in). Also, Therapaws whenever we are outside (I have carpeting in the house). At first, we were hulling every week to 10 days. Now, we are down to about once a month. Dr. Kellogg told me it didn't have to be Kerasolv--there are other similar ointments available--but the idea is to keep the paw pads more pliable--Mandy's are naturally very dry and cracked.
Mandy is a bit of a drama queen, but she seemed to "get it" right away that the Therapaws make it possible for her to walk--without them, she starts limping, shaking, whining, and arching her back in less than 2 minutes outside.
Best of luck in dealing with the corns.