I use a nail clipper to dig right into the calluses and dead skin because I'm too impatient to file 'em down.
I'll try and go with the razor trick. I already got one razor for face, one for armpits and genital area, so I guess I'll designate another one to my hands...
Once and for all:
Calluses decrease performance in the farmer's walk or high-rep pulling exercises. A weaker grip and smaller back are not manly. /Discussion