I'm not sure getting rid of calluses is the best thing. Its our bodies way of protecting our skin from being damaged by a repetitive movement, for example, laying down on the elbows. Those calluses are actually protecting our dogs from hurting themselves. Sure, they look ugly, as they do on humans but in a sense we need them and they need them. Ever felt a guitar players finger tips? They're hard as rocks. But if you ask him what it was like when he first started playing, he might tell you his finger tips hurt a lot. But overtime his body formed a layer of protection, so now it doesn't hurt anymore.