What finally worked for me was locking in moisture within 60 seconds after...

https://mill-wiki.win/index.php/How_Do_I_Protect_My_Chest_from_Sun_If_I_Wear_V-Necks_a_Lot%3F

What finally worked for me was locking in moisture within 60 seconds after showering. I use a simple routine: gently pat dry, then apply a cream with 10% urea on my heels to soften rough patches