i have found using a pincer style grip( forefinger and thumb) on what would be the inside corner of the kettlebell, and this being the emphasis of the grip, during the downswing, greatly reduces the load across the joints where the calluses are likely to form, it takes some getting used to as everything does. as someone stated before, bending the elbow to allow a freefall of the kb allows this grip to work as you are guiding the bell rather than drawing it down.