I have cracks in my hands and feet. For my hand, I use Hand Goo, Beauty Counter handcream and colloidal silver on cracks splits.
I also use Frankincense essential oil on one hand for pain
On feet, I use a Dry Skin salve by Green Goo and an Essential oil blend (Thieves) on top of toes and bottom.
For nails on both feet I make a roller of essential oils (geranium, lemon, peppermint, frankincense, and oregano)-oils good for skin and with immunity properties
I have a first aid salve and Essential oil blend ( both have lavender and helichrysum, one has comfrey and plantain , the other has myrrh. )