You can pull the edges together, put a hydro colloid band aid on, and leave it for several days. Hydro colloid is one word, cannot type it that way though.
I soak my feet in Epsom salts, and while feet are still soft, shave with a foot shaver. You just take a little off whereas if your feet are dry, you can get too much skin off.
People say Boots has a foot grater thing for about six pounds. I am in the states and tried every which way to get that, gave up and bought a $40 diamond sander thing. Which makes feet very smooth. I used to have cracks 1/8" deep and bleeding so start with the hydro colloid band aids just so it feels better immediately.