I rarely touch the sole or frog when trimming. I try to let them shed off naturally. Some horses don't exfoliate sole that well, especially if their feet never really get wet. I try to do daily sprays of ACV to soften the dead sole and let it shed off itself. As for the frogs, I try to let them shed naturally as well. I will pull off any "tags" so as limit the chance of infection setting in but if the whole frog is shedding, I let it be and spray daily with ACV to discourage any infection setting in. If the frog is invading the collateral grooves or is rotted in the sulcus with thrush, I'll trim it then. Otherwise, I leave both alone. Don't fix it if it ain't broke.
There on the tips of fair fresh flowers feedeth he; How joyous his neigh,
there in the midst of sacred pollen hidden, all hidden he; how joyous his neigh